GERM CELLS OF GRYLLOTALPA 297 



parts. Voinov does not show the L-chromosome in division, 

 hence he gives no evidence of how it divides. In conclusion, 

 it seems to me the points which I have mentioned make it very 

 doubtful whether Voinov has correctly interpreted his few obser- 

 vations and also whether his observations are adequate. 



d. Observations of vom Rath and a comparison with my observa- 

 tions made on material collected at Freiburg. Vom Rath ('92) 

 described the spermatogenesis of Gryllotalpa vulgaris. He fig- 

 ured 12 chromosomes in the spermatogonial and six in the 

 maturation divisions. Primarily because of the beautiful rings 

 and tetrads his figures have been widely copied. After finding 

 that the spermatogonial group in the material collected at Naples 

 contained 15 chromosomes, I was anxious to obtain material 

 from Freiburg, where vom Rath collected his, in order to see 

 whether his observations were correct or whether the specimens 

 collected in the two places actually differed in their chromo- 

 some numbers. Through the kindness of Professor Schleip a 

 certain amount of this material was obtained. It was not suf- 

 ficient to give the complete chromosomal history, but the sper- 

 matogonial groups were plentiful and very clear. They demon- 

 strate without a doubt that the correct number is 12 (fig. 5, 

 A, B, C, D). By comparing my figures with those of vom 

 Rath, it will be seen that, while his number is correct, his draw- 

 ings are very schematic. The same is true of his beautiful 

 rings. To be sure rings are present in the prophase of the first 

 division, but they by no means look like vom Rath's figures. 

 Neither do the rings condense into such beautiful tetrads. Side 

 views of the first spermatocyte chromosomes show that only 

 one of the six approaches a typical tetrad (fig. 5, F, G). Figure 

 1, H shows this tetrad in a more typical condition. I mention 

 this in the hope that text book writers in the future will elimi- 

 nate such figures from their books. The few first division figures 

 which are present in my material show six chromosomes (fig. 

 5, E). Figure 5, F and G, side views at different levels of the 

 same spindle, show one of these bivalents unequal. As the 

 spermatogonial group shows one small chromosome, it seems 

 probable that this unequal bivalent is a pair of idiochromosomes. 



