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.