It is said to be invariably the case with the male mule, the cross between the a.s.s and the mare; and hence it is that although crossing the horse with the a.s.s is easy enough, and is constantly done as far as I am aware, if you take two mules, a male and a female, and endeavor to breed from them, you get no offspring whatever; no generation will take place. This is what is called the sterility of the hybrids between two distinct species." (Huxley, _"On the Origin of Species."_ p. 212.) He continues:
"Thus you see that there is a great difference between "mongrels," which are crosses between distinct races, and "hybrids," which are crosses between distinct species. The mongrels are, so far as we know, fertile with one another. But between species, in many cases, you cannot succeed in obtaining even the first cross; at any rate it is quite certain that the hybrids are often absolutely infertile one with another.
"Here is a feature, then, great or small as it may be, which distinguishes natural species of animals. Can we find any approximation to this in the different races known to be produced by selective breeding from a common stock? Up to the present time the answer to that question is absolutely a negative one. As far as we know at present, there is nothing approximating to this check. In crossing the breeds, between the fantail and the pouter, the carrier and the tumbler, or any other variety or race you may name--so far as we know at present--there is no difficulty in breeding together the mongrels." However, he continues, as soon as you remove the conditions which produced the new variety,--as when you permit pigeons to mate promiscuously,--no matter how different the varieties may have been, you will have, in a few generations of pigeons, the same blue rock pigeon with the black bars across the wings. No new species has originated. All varieties, in a free state, revert to type. "This," says Huxley, "is certainly a very remarkable circ.u.mstance."
Fairhurst points out the difficulties in which the evolutionist becomes involved through the fixity of species. He writes: "It is well known that as a rule distinct species will not cross, and that if they do cross the offspring are not fertile. On the other hand, it is true that all _varieties_ of a species readily cross, producing fertile offspring.
This has commonly been regarded as a well-defined distinction between varieties and species. If the varieties of pigeons which are so different from each other did not freely cross, and if the mongrel offspring were not fertile, Darwin"s argument as to the production of new _species_ under domestication would be complete. The fact is, we do not know of the origin of any two species of animals that do not cross and whose offspring are not fertile; in other words, we do not know of the origin of _species,_ but only of _varieties_. The origin of species that will not cross and produce fertile offspring is _a.s.sumed_ from the origin of varieties that do cross and produce fertile offspring. This leaves the evolutionists to account for one of the most difficult things in connection with this theory, namely, how did varieties of animals of the same species become cross-sterile?* [[*So that they were unable to interbreed. Only if such cross-sterility exists, could they exist thereafter as independent new species.--G.]] Several things must occur simultaneously before cross-sterility between parent and offspring could occur and become effective, namely, a number of individuals must be born at the same time possessing the same variation, the variation must be useful, these individuals must be fertile with each other, they must be cross-sterile with the parent form," as, otherwise, the offspring would revert to type, "and, finally, the few, if any, individuals thus produced and being widely scattered through the species, must find each other before they could propagate. I regard it impossible that these things could all occur simultaneously." (_"Organic Evolution,"_ p. 333.)
Mr. Huxley is forced to this admission: "After much consideration, and with a.s.suredly no bias against Mr. Darwin"s views, it is our clear conviction that, as the evidence stands, it is not absolutely proven that a group of animals, having all the characters exhibited by species in nature, has ever been originated by selection, whether artificial or natural." And again. "Our acceptance of the Darwinian hypothesis must be provisional so long as one link in the chain of evidence is wanting; and so long as all the animals and plants certainly produced by selective breeding from a common stock are fertile with one another, that link will be wanting."
In a recent book, _"Creation or Evolution? A Philosophical Inquiry,"_ George Ticknor Curtis says: "The whole doctrine of the development of distinct species out of other species makes demands upon our credulity which the [tr. note: sic] irreconcilable with the principles of belief by which we regulate, or ought to regulate, our acceptance of new matter of belief."
CHAPTER FIVE.
Rudimentary Organs.
Darwinism does not account for the fact that the various organs of animals while in process of evolution, must have through many generations, been in a rudimentary, incomplete state. Since it is a basic doctrine of evolution that useful variations were transmitted from parent to offspring _because they were useful_; and since furthermore, only the fully developed eye, the hearing ear, the actively functioning poison glands of insects and reptiles, etc., as well as the fully developed means of defense, were useful, it is not possible to understand how these organs in their rudimentary state (the half developed eye, not yet capable of vision; the rudimentary spinneret of the spider, not yet capable of producing a thread, etc.) could serve any purpose which would make their transmission advantageous to the species.
Conversely, the existence of rudimentary organs in living species (the rudimentary spurs of female birds, the rudimentary legs of skeleton of serpents) proves that organs do not change by use or disuse, otherwise they would long ago have disappeared.
With regard to this difficulty, Darwin says: "If it could be demonstrated that any complex organ existed which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case." Let us see.
A difficult organ to account for is the electric organ of the skates. In these fishes it has been shown to be a true electric battery, but the discharges from this battery, even in the adults, are so feeble that they are of no practical use so far as has been ascertained. It is well known that the electric eel and the torpedo use their batteries for stunning other animals. It is evident that, according to the theory of natural selection, these batteries could not have been preserved through their long functionless and useless stages, for that theory a.s.sumes that they were preserved because they were useful.
It is a.s.serted by evolutionists that wings as organs of flight have been independently evolved in at least four different lines--namely, in insects, the fossil pterodactyls, birds and bats. That an organ so highly specialized as any one of these wings could be evolved seems improbable; while the evolution of the four different kinds, independently of each other, only increases the improbability. The difficulty, however, is to account for the evolution of any known kind of wing. In each case there exists the insuperable difficulty of preserving the organ through the rudimentary stages. The wings of an insect in the first generation of its evolution would be almost imperceptible and entirely useless for any purpose whatever, and so it would continue to be for a great number of generations. It is evident, therefore, that they could not have been preserved through their long rudimentary stage on the ground that they were useful, nor do we know of any theory that will account for their evolution. To say that they were evolved is easy, but to account for their evolution seems impossible.
Fairhurst refers to the delicate and complex organs of spiders. "The organs which spiders possess for secreting material and for making a web could not have been gradually evolved. The whole apparatus involved in making the web would be useless until sufficiently developed to make a web. The same is true," he continues, "of the sting of the scorpion, the stings of bees, the mandibles of spiders with the gland of poisonous fluid at the base, and the poison apparatus of serpents. All of these glands for secreting poison would be useless until they could secrete a harmful fluid. The spurs of birds present further difficulties to the theory of evolution. Most birds have no spurs. When they possess them, as a rule the males alone have them well-developed, while they are rudimentary in the females. In some cases, however, both s.e.xes possess them in a well-developed form. But how could a spur be evolved in either s.e.x? As a rudiment, it would for many generations be entirely useless for any purpose, and consequently it would not be preserved by natural selection, nor in any other possible way, so far as I can see. The spurs are in the best possible position on the legs for combat. Why did they appear in the best place and nowhere else? As useless rudiments they would be quite as likely to survive in one place as in another. If spurs could not have been preserved by natural selection through their rudimentary stage, why a.s.sume that they have been evolved according to this law? If they could survive through the critical rudimentary period till they became of use, why not a.s.sume that their evolution was continued according to the same law? The fact is, however, that we know of no law according to which they could have been evolved." The bat is another highly specialized animal. In many respects it resembles the mole, but its hands are, enormously expanded, and the exceedingly long fingers are connected by a soft membrane, making a most serviceable wing.
It is not extremely likely, a.s.suming the development theory to be true, that both the mole and the bat sprang from a common ancestor? And was not that ancestor probably a wingless, though not a legless mammal? Now, how came the bat to acquire his wings? Did he attempt to spring into the air and seize a pa.s.sing insect, and reach out his paws to catch it? And did those paws gradually become enlarged, till, after some generations, they were real wings? But what happened in the meantime to those connecting links whose wings were but partly developed? A bat with wings only half grown would be a helpless creature, and would surely perish. A mole with hands terminating in long, slender fingers, would be helpless, and would perish. There is no middle ground. If the ancestor of the bat was a terrestrial creature, with limbs fitted for walking, then it must have given birth to a full-fledged bat, fitted for flying. There could have been no middle stage, for such a creature would have been helpless, and must have perished.
All this applies with equal force to the diversified and often highly complex structure of plants. As the organs of the various plants are now const.i.tuted, they most admirably serve their purpose. Given a slight change, an underdevelopment, and the individual would perish. But such underdeveloped stages must have occurred in the history of every life-form on earth, if a change through slow adaptations is to be accepted as a hypothesis to account for their present form. To our mind, this matter of rudimentary structures presents an insuperable obstacle to acceptance of the evolutionary hypothesis even on scientific grounds.
CHAPTER SIX.
Instinct.
How the various instincts of animals, the homing instinct of birds and insects, the building instincts, the migrating instinct, etc., could have been developed though forces working by natural selection or any other law, is a question which has called forth much discussion. It cannot be said that the explanations contained in the pages of Darwin, Romanes, and Spencer are satisfying. The difficulty that remains unsolved is similar to that (already considered) of rudimentary structures. On instinct depends the existence of most animals.
According to the theory these instincts have been developed by slow degrees. Hence there must have been a time when these instincts, because not yet completely developed, were useless to the animal. But if useless, the animal must have perished. The strength of this objection to the evolutionary hypothesis will become clear from a brief study of the manner in which animal life is bound up with the proper functioning of instinct.
Consider, for instance, the dependence of the honey bee and her hive on the functions, every one instinctive, of queen, workers, and drones.
There is the queen, whose sole work is to lay eggs; the drones, or males, whose function it is to fertilize the queen; and the workers, which are females undeveloped s.e.xually. In these three kinds of individuals we see a combination of many most remarkable instincts and peculiarities of structure which look to the good of the community. How could they have been produced by evolution? The workers are sterile and leave no offspring, consequently their instincts cannot be inherited from bees of their own cla.s.s. Each generation of workers is isolated from all succeeding generations. A colony of bees is not like a community of civilized human beings in whom many of the wants are artificial, and which may remain unsupplied, with simply a certain amount of discomfort, but the wants which the instincts of bees supply are imperative, and, therefore, the instincts themselves, as a whole, are necessary to the existence of the bees. Their instincts are all linked together as a necessary chain, so that if one should fail the community would perish. Each kind of work is perfectly done, and yet the workers are totally unconscious as to what will be the result of their labors. For the most part they work for future generations of their colony, and not for themselves, and yet they are as careful and diligent as if they were guided by the highest intelligence and the most selfish motives [tr. note: sic no punctuation]. Fairhurst, whom we are quoting, adds: "There is nothing more wonderful and mysterious in nature than the instincts of bees. What can be more remarkable than that instinct of the workers which causes them to prevent the queen from stinging to death the young queens in their cells? Here we see the instinct of the workers opposing that of the queen, and thus saving the colony and insuring the propagation of the species. And yet at other but proper times the workers permit the old queen to kill the young ones in their cells. How could these instincts in the workers, which act in exactly opposite ways by just the right times for the welfare of the community, have ever been evolved? Or how could that instinct have arisen which causes two queens when engaged in combat to refrain from inflicting the mortal sting if they would mutually destroy each other, and thus leave the hive without a queen?--acting as if they knew that the life of one of them was necessary for the welfare of the community."
Concerning the modifications of structure and the instincts necessary to produce the web of the spider, Fairhurst quotes the following from Orton"s _"Zoology."_ "Spiders are provided at the posterior end with two or three pairs of appendages called spinnerets, which are h.o.m.ologous (correspond structually) [tr. note: sic] with legs. The office of the spinnerets is to reel out the silk from the silk-glands, the tip being perforated by a myriad of little tubes through which the silk escapes in excessively fine threads. An ordinary thread, just visible to the naked eye, is the union of a thousand or more of these delicate streams of silk. These primary threads are drawn out and united by the hind legs."
From this we see that two special glands, capable of secreting a soft material that can be readily drawn into the finest threads of the greatest strength, requiring no perceptible time for drying, and two to four spinnerets perforated by more than a thousand of the smallest apertures, and hind legs modified so that they can be used to draw out the web through the spinnerets, and also the instincts which enable the spider to use its web to advantage, must all have been evolved. To evolve the silk glands would have required, as for most other organs, a long period of incipiency, during which they would have been useless.
We can not a.s.sume that a substance so exceptional in its character as the web of the spider could have been suddenly produced by evolution.
But the glands would be useless without spinnerets. The hypothesis asks us to a.s.sume that two or three pairs of legs that were probably at one time useful for locomotion became so modified that they could perform the function of spinnerets. But in what conceivable way could locomotive legs have become so modified and pierced with more than a thousand apertures through which the web is drawn? And how could these organs serve their purpose while the complex instincts required for their functioning were only in course of development?
From a German monthly devoted to aquaria, we quote the following: "But now, dear readers, we come to a fish which shows an exceptionally peculiar and touching care for its young--the mouth-brooder, _Haplochromis Strigigena_ (formerly _Paratilapia Multicolor_). This fish is so much concerned about the safety of its young, that it knows no better and no more secure place than its own mouth in which to preserve them. In no other division of the animal kingdom can we find such an interesting example of fostering care for the young as we find in this species of fish. Immediately after emitting the sp.a.w.n the female again gathers up the eggs and packs them away in her mouth like herring in a barrel. She naturally must employ the organs of the throat and also the organs between the gills and thus the appearance of the animal is greatly changed even to the extent that it looks very much like as if she had a craw. Furthermore, during ths [tr. note: sic] entire period, which is about fourteen days, the little animal cannot take food and is hampered very much in her movements. Therefore in case of imminent danger it becomes necessary for her to cast out the entire brood which then wretchedly perish, and for this reason it is to be recommended to disturb or disquiet these animals during this period as little as possible. Even after the young leave the mother of their own accord, they always flee to her protecting mouth, and thus they present an exciting aspect, when they are first seen peacefully and contentedly playing about the mother fish, until a shadow or a sudden thrust warns them of danger and quick as lightning they dart into her mouth.
"If the fostering care of this mouth-brooding fish is regarded as wonderful and singular, what should one then say, if another fish is spoken of which does not regard this kind of protection as sufficient, and which therefore causes its eggs to hatch outside the surface of the water. The exceedingly adorned and elegant _Phyrrhylima Filamentosa_ performs this masterpiece of truest love. With great dexerity [tr. note: sic] this fish darts from 5 to 7 cm. above the surface of the water and there fastens its eggs on the walls of the aquarium--usually in one corner. Even though one must and can preserve damp air by covering the aquarium, the sp.a.w.n would nevertheless surely dry up, if the fish itself were not constantly concerned to keep the sp.a.w.n damp by an extended bombardment of little drops of water. In the performance of this act the fish remains near the surface of the water and then by a quick upward movement of the fins of the tail it throws a drop of water upon the sp.a.w.n in such an expert manner as is truly admirable. One must also keep in mind here that the sp.a.w.n require from three to five days for hatching, and now one can understand what a huge task this little fish performs and what efforts are required. Later on the young hatch and then slide down the slick wall of the aquarium into their native element." (V. Schloemp in _"Blaetter fuer Aquarien und Terrarienkunde,"_ Stuttgart, Sept. 1913.)
In all the domain of natural science there are no wonders more amazing than those of instinct. The subject is simply inexhaustible. Moreover, every animal is absolutely dependent on instinctively performed actions and habits. The life-story of many wasps, of the various ants,--someone has called the brain of the ant the most wonderful speck of protoplasm in the world,--and of the insects generally, is bound up with instincts that partly interlock marvellously with the life-story of plants, and which are, even viewed in themselves, the greatest wonders of creation.
The questions insistently call for an answer: How could these instincts preserve the animal when they were still in an incipient, undeveloped state? How could they arise through natural selection (which is simply _accident,_ of course), at all? Darwin says that there are instincts "almost identically the same in animals so remote in the scale of Nature, that we cannot account for their similarity by inheritance from a common progenitor, and consequently must believe that they were independently acquired through natural selection." Again he says "Many instincts are so wonderful that their development will probably appear to the reader a difficulty sufficient to overcome my whole theory."
And here, in the vernacular of the day, we would depose that Mr. Darwin _"said something."_
CHAPTER SEVEN.
Heredity.
The subject of heredity is intimately bound up with the evolutionary hypothesis and, it must be admitted, creates a new difficulty for the acceptance of the theory. Indeed, the laws of heredity, so far as understood, appear to contradict the theory of Lamarck and Darwin at a vital point, if not at _the_ vital point of the entire structure raised in the _"Origin of Species."_ It is necessary in order to appreciate the strength of this objection, to recall once more the outstanding features of the hypothesis by which scientists have attempted to account for the variety of living forms. The various theories of organic evolution, whether Lamarckian, neo-Lamarckian, or Darwinian, are based upon the a.s.sumption that animals and plants have a tendency to perpetuate by transmission to offspring a variation which has proven useful as an aid to the particular species in its struggle for existence. We have just discussed, in the chapters on the Fixity of Species and on Rudimentary Organs, certain difficulties which loom up when the question is raised, How did varieties become distinct species? However, even if it were to be a.s.sumed that some satisfying answer might be found to this question so far as the stages of incomplete organs are concerned, there is one fact in heredity which, it would seem to me, strikes at the very heart of the theory.
In his _"Philosophic Zoologique"_ (1809), Lamarck first explicitly formulated his ideas as to the trans.m.u.tation of species, though he had outlined them as early as 1801. The changes in the species have been wrought, he said, through the unceasing efforts of each organism to meet the needs imposed upon it by its environment. Constant striving means the constant use of certain organs, and such use leads to the development of those organs. Thus a bird running by the sea-sh.o.r.e is constantly tempted to wade deeper and deeper in pursuit of food; its incessant efforts tend to develop its legs, in accordance with the observed principle that the use of any organ tends to strengthen and develop it. But such slightly increased development of the legs is _transmitted to the offspring_ of the bird, which in turn develops its already improved legs by its individual efforts, and transmits the improved tendency. Generation after generation this is repeated, until the sum of the infinitesimal variations, all in the same direction, results in the production of the long-legged wading-bird. In a similar way, through individual effort and _transmitted tendency,_ all the diversified organs of all creatures have been developed--the fin of the fish, the wings of the bird, the hand of man; nay, more, the fish itself, the bird, the man, even.
Note well, the fundamental a.s.sumption is that such acquired characteristics,--greater length of leg, or of neck, a coating of hair, a protective coloring, etc.,--however acquired, can be transmitted from the parent animal possessing them, to its offspring. The question arises: Can such characteristics be transmitted? And the students of heredity answer: They _cannot!_
I find in G. Archibald Reid _"Alcoholism, a Study in Heredity,"_ a lucid exposition of this subject. (Reid is a F. R. S. E. His book was published by T. Fisher Unwin, London, a few yars [tr. note: sic] ago.)
"All the characters of a living being, every physical structure and every mental trait, may be placed in one of two categories. Either they are inborn or they are acquired. An inborn or innate character is one which, in common parlance, arises in the individual "by nature."
Thus arms, legs, eyes, ears, head, etc., and all inborn characters.
The child inherits them from his parent. But, if during its development, or after the completion of the development any one of the inborn characters of an individual is modified by some occurrence, the change thus produced is known as an acquired character, or, shortly, as an acquirement.
"Thus all the effects of exercise are acquirements; for example the enlargement which exercise causes in muscles. The effects of lack of exercise are also acquirements; for example, the wasting of a disused muscle.
"The effects of injury are acquirements; for example, the changes in a diseased lung or injured arm. Every modification of the mind is also an acquirement; for example, everything stored within the memory.
"If a man be blinded by accident or disease, his blindness is acquired.
But if he comes into the world blind, if he be blind by nature, his blindness is inborn. If a son be naturally smaller than his father, then his inferiority of size is inborn; but if his growth be stunted by ill health or lack of nourishment or exercise, his inferiority is acquired.
"Lamarck held, as people in all ages have held, that characters acquired by parents are also transmissible to some extent, and that evolution results from their accentuation during succeeding generations. _Lamarck"s theory is rejected totally by the modern followers of Darwin_.
"Ten thousand men might break their fingers, yet among their offspring not one might have a crooked finger. Consider on the other hand for how many generations women have bored their ears and noses in India. Yet when is a girl born with ears and nose already pierced? For how many generations have we amputated the tails of terriers, and yet their tails are no shorter. It will then be perceived how overwhelming is the case against the doctrine of the transmission of acquirements.
"The general question of the transmission of acquirements is too big and too abstruse to be treated adequately here. Two arguments more I may use, however, partly because they have not been developed, to my knowledge, by other writers, and partly because they seem to me well-nigh decisive. The more than normal development of the blacksmith"s arm is rightfully called an acquired trait, since it arises from exercise, from use, not from germinal conditions. But no infant"s arm develops into an ordinary adult arm without exercise similar in kind to that which develops the blacksmith"s arm, though less in degree.
"Every single thing contained within the memory of man, every single word of a language, for instance, is an acquirement. But when are the contents of a parent"s mind transmitted to the child?
"Again, a man is capable of becoming a parent at any time between extreme youth and extreme old age; a woman from the age of thirteen to fourteen till nearly fifty. Between the birth of the first child and the last such an individual changes vastly. Under stress and fear of circ.u.mstances, under the slings and arrows of outrageous fortune, all sorts of acquirements are made. The body becomes vigorous and then feeble, the mind grows mature, and then senile. He or she grows wrinkled and bowed and perhaps very wise, or perhaps much the reverse.
Yet no one viewing a baby show, a children"s party, or an a.s.sembly of adults, of whom he has no previous knowledge, can say which is the child of the youthful and which of aged parents.
"Apparently, therefore, the whole of the parent"s acquirements have no effect on the child. _Surely no evidence could be stronger."_* [[* The undoubted transmission of siphilis [tr. note: sic] to off-spring might be regarded as a case of transmission of an acquired characteristic. But the case is not in point since congenital siphilis [tr. note: sic] is, properly, due to a prenatal infection, the bacillus entering the very germ-plasm of the human ovum (egg). Medical science, generally, has become very cautious in the use of the word "hereditary." There is almost unanimity among medical men in the denial of heredity as a factor in tuberculosis and cancer. Most physicians are honest enough to say that they know considerably less about these things than was "known" ten and twenty years ago.]]
Herbert Spencer claims that "the inheritance of acquired characters" is a necessary supplement to natural selection. "Close contemplation of the facts impresses me more strongly than ever with the two alternatives--either there has been inheritance of acquired characters, or there has been no evolution." Again, "the inheritance of acquired characters, which it is now the fashion of the biological world to deny, was by Mr. Darwin fully recognized and often insisted on." "The neo-Darwinists, however, do not admit this cause at all." He admits that known facts which show that acquired characters are inherited are few, but he thinks that they are "as large a number as can be expected, considering the difficulty of observing them and the absence of search."
From the above, we see that the biological world is against Mr.
Spencer"s view; that he would abandon the theory of evolution unless acquired characters had been inherited, but that facts in support of this theory are meager. "Biologists in the above instance, as well as in others, differ in theory as to fundamental principles of evolution. He who imagines that the theory of organic evolution has been proved to the point of demonstration, has but to read the contentions of evolutionists themselves with regard to the most important things involved in the theory, in order to satisfy his mind that there is great diversity of opinion." (Fairhurst.)
The general abandonment of the Darwinian hypothesis by biologists, adverted to in our next chapter, is mainly due to the failure of heredity to account for the gradual modification of organs and of habits.
Various expedients are resorted to by Haeckel and a few others in their attempts to bolster up a theory which has broken so signally on the rock of heredity. Princ.i.p.al among these is the reference to unlimited time. It is a.s.serted that, after all, such minute differences might, in the course of many ages, result in new and more perfect organs. However, here a new and unexpected difficulty presents itself. The physicist, who has measured the heat of the sun, rises up and says that the age of the earth, as estimated by specialists like Lord Kelvin, is not nearly so great as is demanded by the Darwinian. The period which the physicists, in their mercy, appear to be willing to grant the inhabitable globe is from twenty to forty million years. But the evolutionists maintain with great fervor that this period is far too short for the production of such complicated types of organism as now live on the earth; they demand from two hundred to a thousand million years! And so these two groups of scientists, the evolutionistic biologist and the physicists are hopelessly at odds.
A new generation of evolutionists has within the past twenty years arisen which holds that the changes in the organizations of plants and animals do not come by slow growth of favorable characteristics, but arise suddenly. Such is the "Mutation" theory of Hugo de Vries. But science has failed to receive this and similar theories with the same acclaim which once greeted Darwin"s _"Origin of Species."_ Naturalists have become cautious. They remember the inglorious collapse of the Darwinian regime and they are slow to hail another "Abraham of scientific thought." They are, in a general way, believers in some kind of evolution; but they prefer not to specify exactly the laws which have been operative in past "geological time." It is only in high-school texts in physical geography, zoology, and botany, that the evolutionary theory as propounded by Darwin is still treated as if it enjoyed among scientific men the same respect as the multiplication table. Speaking in the Darwinian dialect we should say that the authors of these school-texts const.i.tute a case of "arrested development."