320 



C. E. MCCLUNG. 



importance to the condition until I recently encountered it in a 

 number of other forms. 



The spermatogonia of this genus show numerous pairs of 

 chromosomes when viewed from the pole, in which the evidence 

 of the end to end union of univalent chromosomes is unmistak- 

 able. The number of these pairs is not constant, but as many 

 as four have been encountered in one cell. A side view of an 



FIG. 17. Lateral view of a 

 spermatogoniimi of Chortophaga 

 in metaphase. The separation 

 of multiple chromosomes along 

 with simple ones is well shown. 

 This is another good illustration 

 of heterotypical divisions in the 

 spermatogonia. 



FIG. 18. A polar view of a 

 similar cell in which appear four 

 tetrads. This is an exceptionally 

 good illustration of early synapsis 

 of the chromosomes. 



anaphase shows very clear heterotypical divisions among the 

 chromosomes, the remainder of which are divided in the usual 

 way. The subsequent history of these I have not worked out. 



5. Certain Chromosomes of Anabrns. 



During the course of my studies upon Locustid genera I was 

 caused not a little difficulty by an oddly formed chromosome in 

 the spermatocytes of the genus Anabrns. At the time I was 

 obliged to confess myself beaten in the endeavor to determine the 

 constitution of this element. That it had to do with the acces- 

 sory chromosome I was thoroughly convinced, but that it was 

 unusual in some way I was equally assured. Not until I had 

 become familiar with the hexad multiple chromosome of Hes- 

 pcrotcttix did the matter clear itself up. Having learned the pos- 



