202 KANSAS UNIVERSITY SCIENCE BULLETIN. 



is to be observed, however, that the derivation of the spireme 

 from the disintegrating chromosomes of the previous genera- 

 tion is not so clearly indicated in the Locustid cells, and it was 

 for this reason that in the examination of Xiphidium I was not 

 able to determine certainly that the accessory chromosome came 

 over from the spermatogonia into the spermatocytes as a formed 

 element. Upon this point, as upon others, my later material 

 is clearer, and I was able to reconcile the appearances in the 

 two families. In both, unfortunately, it has been found im- 

 possible to determine the exact origin of the first spermatocyte 

 chromosomes. 



In connection with the transformation of the chromatin from 

 the spermatogonial condition to that of the spermatocyte, we 

 must take notice of that stage which is commonly denominated 

 the "synapsis." The evidence afforded by the Orthopteran 

 cells is entirely negative regarding this. In properly fixed ma- 

 terial there is no distortion of the chromatin in the nucleus at 

 any time. It would, if present, be particularly easy to observe, 

 as was stated in my previous paper, for during the entire win- 

 ter the spermatocytes exist in the spireme stage, and in a longi- 

 tudinal section of a follicle all stages may be discerned. On 

 the other hand, in poorly fixed or hastily prepared material the 

 synapsis is present, and always in such a form as to indicate 

 its artificial character. What is here said regarding the syn- 

 apsis refer to the appearance commonly thus designated, but, 

 as has already been stated, such an application of the term does 

 not meet the spirit of the definition as intended by Moore (20) . 

 A fusion of the spermatogonial chromosomes of some sort must 

 certainly occur, but that it is always marked by a unilateral 

 massing of chromosomes, I deny. 



During tlie prophase the chromatin segments in the cells of 

 Orchesticus and other species of the Locustids are heavier, more 

 granular and denser than they are in H)ppixcns. It is to be 

 observed, also, that there is a greater variation in the size of 

 the elements. This fact is observable from the earliest appear- 

 ance of definite segments down through both the spermatocyte 

 mitoses. This disproportion may be such that one chromosome 

 will exceed another in the same cell by twenty or thirty times 

 its volume. We have here, as is pointed out in another place, 

 a strong proof concerning the individuality of the chromosomes, 



