WATER BUGS AND BEETLES
Water Bugs
_Materials._
Water bugs and beetles of several species in small aquaria covered with a wire net.
_Observations._
1. With what legs does the bug swim? Describe their appearance and tell how used and how fitted for this use. Which legs are not used in swimming?
2. Remove the bug from the water for a moment to test other methods of locomotion, as jumping, crawling, flying. What do you discover?
3. Watch the bug as it gets a fresh supply of air, and describe the process. Where is the air stored for use when under water? Does the bug sink or rise when it stops swimming? Why?
4. Identify the bug"s mouth parts. What is their appearance and probable manner of use? How are the forelegs fitted for grasping food?
5. What is the shape of the body? What is the position of the wings?
Do the two cover (fore) wings meet in a straight line or do they cross at their tips? Are they smooth throughout and sheath-like, or are they thick at the base and thin at the tips?
_Summary._
Summarize your study of the bug by enumerating the various ways the bug is adapted for life in the water.
Water Beetles
Use the same questions for the study of water beetles as for water bugs. In addition answer the following:--
1. Identify the eyes of the whirligig beetle and note their peculiar construction. How can you explain this peculiar form of the eyes on the basis of use? Why are the antennae of both water bugs and beetles so small?
_Suggested drawings._
a. The dorsal view of both bug and beetle.
b. Ventral view of the bug"s head to show the beak and first pair of legs.
GETTING ACQUAINTED WITH THE LIBRARY
_Directions._
The books in a zoological library may be roughly divided into three groups:--
1. Reference books.
a. Advanced textbooks.
b. Elementary textbooks.
c. Natural histories.
d. Books for cla.s.sifying or naming animals.
2. Descriptive books.
e. Life histories and habits of animals.
f. Adventures with animals--popular accounts of animals seen on walks and travels.
3. Economic zoology.
g. Books on harmful animals and methods of destroying them.
h. Books on useful nondomesticated animals and their products.
i. Books on domestic animals.
j. Books of a general nature not included in the above.
Examine as many of the books in your library as you can and record for each one in your notebook:--
1. t.i.tle of the book; author"s name; publisher; date of publication.
2. The kind of book as cla.s.sified above.
3. What it includes or what animals or topics are covered by the book.
4. Whether the style is popular or technical, _i.e._ whether it is easy for you to read.
5. The general character of its ill.u.s.trations and whether they appear to be especially helpful.
6. Comments on the value or interest of the book as it appears to you.
7. Select a book which interests you, for future reading.
CHAPTER II
STUDIES OF INSECTS
_The effect of great numbers upon the structure and habits of animals. The use of keys in finding the names of animals._
1. FIELD STUDIES
_Materials._
1. _Boxes_ for carrying insects. 2. A _net_. This may be homemade, using mosquito netting or fish net and a stout wire. If it is to be used for a dragnet for water insects, the wire must be stout and the netting strong. Make the net twice as long as wide. 3. A _cyanide jar_ for killing insects. 4. A few _paper triangles_ for carrying b.u.t.terflies. 5. A _notebook_.