222 KANSAS UNIVERSITY SCIENCE BULLETIN. 



would not be necessary to consider it here except in so far as it 

 has been modified since its promulgation. As a rule, Mont- 

 gomery refers to his "chromatin nucleoli" throughout his late 

 paper (15) as degenerating chromosomes, but in discussing 

 their function specifically he makes important changes in this 

 conception. These are stated as follows : "When we find, ac- 

 cordingly, the mutual apposition of them (true nucleoli) to 

 chromatin nucleoli, it would be permissible to conclude that 

 the chromatin nucleoli are chromosomes which are especially 

 concerned with nucleolar metabolism. And this, I think, would 

 be the correct interpretation. The chromatin nucleoli are in 

 that sense degenerate that they no longer behave like the other 

 chromosomes in the rest stages, but they would be specialized 

 for a metabolic function ; and from this point of view they 

 would certainly seem to be much more than degenerate organs." 



It is difficult to comment upon a contradictory statement like 

 this ; but, fortunately, it is not necessary to do so, since it carries 

 with it its own refutation. The conception of a chromosome 

 specialized in the direction of increased metabolic activity as 

 being in the process of disappearing from the species can hardly 

 be regarded seriously. 



Taking everything into consideration, it may be said that 

 Montgomery's work upon the Hemiptera has left the subject in 

 a very disturbed condition, and any prospect of a complete 

 agreement between the accessory chromosome of the Orthop- 

 tera and the "chromatin nucleolus" of the Hemiptera is made 

 more remote than was previously the case. This, I think, is 

 largely due to the inferior character of the Hemipteran mate- 

 rial, which has lead to misconception of phenomena that are 

 clearly marked in Orthopteran cells. 



It is gratifying to note that the recent work of de Sinety (37) 

 practically corroborates the conclusions herein set forth regard- 

 ing the history of the accessory chromosome. Aside from fail- 

 ure to observe the important spireme condition of this element 

 in the first spermatocyte prophase, de Sinety describes the same 

 series of processes with scarcely an exception. His summary 

 contains the following account of the accessory chromosome : 



"Le 'chromosome accessoire,' d^couvert par McClung chez Xiphidium 

 fasciatum, se retrouve chez les locustiens que nous avons ^tudi^s. Chez Or- 

 phania, il se divise dans les spermatogonies en deux masses volumineuses et 



