GERM CELLS OF GRYLLOTALPA 293 



of chromosomes and an accessory chromosome, the distribution 

 of which is a random one. 



Fortunately, I also have some material of the European mole- 

 cricket. I believe that Gryllotalpa vulgaris is the only species 

 described in the whole of Europe. If there is only one species, 

 I presume my material, some of which was collected at Naples 

 and some at Freiburg, Germany, is also that of Gryllotalpa vul- 

 garis. Mr. A. N. Caudell, of the Bureau of Entomology, Wash- 

 ington, D. C., has made a critical examination of my specimens 

 and reports that he is unable to find any specific differences. 

 The chromosomes, however, in the material collected at these 

 places, are different. Whether this chromosomal difference con- 

 stitutes a specific difference, matters but little. The principal 

 point is that the material collected in these two places differs in 

 at least this one respect. It seems that we here have a case 

 similar to the one described by Wilson in Thyanta custator 

 where he finds different chromosome numbers in material col- 

 lected in New Jersey and in the South and West. 



b. Observations of Voinov. In Gryllotalpa vulgaris, Voi'nov 

 ('12) describes 14 chromosomes in the spermatogonia group 

 (fig. 3, A). As one needs his figures to compare with my own, 

 I have copied them. Figure 3, A, B, C, and D are from his first 

 and figure 3, E and F from his second paper. One of the sper- 

 matogonial chromosomes, the small one, he labels 'm-chromo- 

 some' and another 'X-chromosome.' Just why he labels only 

 one chromosome an m-chromosome, when he figures the 

 m-chromosome in the first spermatocyte division as a bivalent, I 

 do not understand. It seems to me there should be two 

 m-chromosomes in the spermatogonial group. Further, I do not 

 see how he is able to pick out the X-chromosome at this time. 

 A side view of the X-chromosome in the first division (fig. 3, D) 

 is also interesting. He figures and describes it as constricted 

 into three parts. In this division he says one small part goes 

 to one pole, the dyad to the other, while in the second division 

 both parts divide. If he means to use the term 'X-chromo- 

 some' in the sense in which it has been used by American writers, 

 I do not see how such a chromosome as he figures and describes 



