PLATE 3 



EXPLANATION OF FIGURES 



Oncopeltus, from sections excepting 65, which is from a smear-preparation. 

 Enlargement 2250 diameters. 



47-48 Spermatogonia! telophases. It is uncertain whether this is the last divi- 

 sion or an earlier one. 



49 Later spermatogonia! telophase. Probably Stage a. 



50-51 Stage h, showing the massive chromatic bodies, the sex-chromosomes 

 readily distinguishable. 



52-55 Stages h-c, showing the process of unravelling. 



56-59 Stage d. Leptotene-nuclei. 



60 Transition to the synizesis. Synaptic period. 



61 Stage e. Synizesis, from a very clear specimen. 



62 Transition to the following stage. 



63 Stage /. Pachytene-nucleus. The threads apparently undivided. 



64 Stage /. Diplotene-nucleus. 



65 (photo. 10). Stage/. Diplotene-nucleus, from a smear-preparation. 

 66-67 Stage g. The confused stage, showing plasmasorne and both chromo- 



some-nucleoli (sex-chromosomes). Plasmasorne at its maximum size. 



436 



