CHROMOSOME COMPLEX OF SPERMATOCVTES. 305 



already been embodied in papers devoted to the Orthopteran 

 families. 



During the course of these investigations it became plain that 

 there were variations from the type of maturation mitoses, and 

 that these afforded facts which seemed to indicate that it might 

 be possible to discover some correlation between individual chro- 

 mosomes and body characters. It is the purpose of this paper 

 to bring forward some of these facts and to suggest conclusions 

 arising from our thus increased knowledge of the maturation 

 chromosomes. In venturing these deductions I have had in 

 mind their application to the particular forms studied, but at all 

 times have tried to bring them into relation with facts derived 

 from the study of other organisms. This, I believe, is justifiable 

 in the present state of our knowledge, for it is done on the sup- 

 position that reproduction is, in 'the main, the same process 

 throughout the range of organic forms. With the accumulation of 

 observations the conviction is borne in upon us that the matura- 

 tion mitoses of all organisms are, in general, of one pattern, and 

 that the burden of proof lies upon him who would argue for 

 individual types. 



There is always the danger, to be sure, that we have not 

 reached down to the basic facts, but are conceiving more super- 

 ficial ones to be all important. This is, I imagine, unavoidable 

 in the preliminary stages of an investigation, but it can lead to 

 no harm if the facts in each case have been accurately deter- 

 mined. In the absence, therefore, of definite knowledge of the 

 chromosomes in the germ cells of organisms exhibiting Men- 

 delian characters or mutations we are warranted in supposing 

 them to be of the same general character as the ones known 

 until they are proved different. 



The present paper is one of a series in which it is hoped to de- 

 velop the history of the maturation chromosomes in the Orthop- 

 tera. Obviously this is a task of great magnitude and no far- 

 reaching conclusions can be attained until a large series of forms 

 has been studied. Already a not inconsiderable number has 

 been worked over, and each year additions are made. Recently 

 I have been devoting myself again to the family Acrididas, and in 

 some newly observed forms I have encountered certain peculiar!- 



