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DESCRIPTION OF PLATES.
[The figures of plates I-VI were all drawn with Zeiss oil-immersion 2 mm., oc. 12, and have been reduced one-third; those of plate VII with oc. 8, not reduced.]
PLATE I.
_Termopsis angusticollis._
FIGS. 1-3. Resting nuclei of spermatogonia, showing division of nucleolus.
4. Equatorial plate of spermatogonial mitosis, 52 chromosomes.
5-6. Young spermatocytes, showing division of nucleolus.
7. First maturation spindle, and two nuclei (6 and 8) in same cyst.
8-10. Skein-stage--so-called synapsis-stage.
11-14. Bouquet-stage, showing two nucleoli, centrosome (_c_) in fig. 11, and loops made up of fine, then coa.r.s.er granules.
15-17. Stage following preceding; loops straightened out and extending in various directions through nucleus.
18. _a_, Chromosomes much shortened and longitudinally split; _b_, chromosomes contracted to form diamond-shaped figures.
19. Stage between 18_a_ and 18_b_.
20. Stage between 19 and 18_b_.
21. Stage similar to 18_a_, one chromosome in double diamond form.