3io 



C. E. MCCLUXG. 



also a qualitative division of the accessory chromosome which 

 here exhibits the same behavior as has been described for the 

 Locustids, the difference being that in the case of Hesperotettix 

 there is a close association between the accessory and an ordi- 



___ nary tetrad. It would seem 



that there is here an attempt 

 on the part of the accessory 

 chromosome to establish the 

 usual relationships that are 

 formed between chromosomes 

 at this period of the matura- 

 tion process. To this extent 

 the element departs from what 

 has been regarded as one of 



FIG. 4. Polar view of first spermato- 

 cyte metaphase, Hesperotettix, showing all 

 the chromosomes of the complex. 



its most characteristic features, 

 that of exclusiveness. As a 

 matter of fact, however, all the 

 later work upon this structure has tended to show similarities to 

 ordinary chromosomes rather than differences from them, and we 

 are not surprised, therefore, to find it uniting itself with another 



a 



\t'!%iiw\* 



\ ':"' ' ,..' l'V'.-'? \ ' 



FIG. 5. Lateral view of one pole of first spermatocyte anaphase, Hesperotettix, 

 with four chromatic elements drawn. The multiple chromosome at the left consists 

 of the accessory chromosome and one half of the tetrad to which it was united. The 

 relative positions are the same as in Fig. 3. Fig. $a represents such a multiple 

 chromosome en face. 



chromosome in the ordinary manner. Being the odd member of 

 the group it is unable to accomplish this step in the usual way 

 and is therefore forced to become a member of a hexad element. 



