HISTORY OF CHROMOSOMAL VESICLES IN FUNDULUS. 277 



its functions and behavior are dynamic. Child has pointed out 

 with great propriety that " instead of being the basis the chromo- 

 some is itself a problem of heredity." We no longer think of 

 chromosomes as ultimate units of structure or the unreducible 

 cause of heredity processes. It is true that the heredity proc- 

 esses have been merely pushed farther back into the cell for 

 explanation; but even then, a distinct step has been taken if the 

 correlation can be traced as in Drosophila, between body char- 

 acters and chromosomes ; and a more complete dynamic explana- 

 tion of the processes, along with that of chromosome structure 

 and behavior, can only be eagerly awaited. Dynamic processes 

 are of course at the basis of all biological functions; with the 

 physical structure of the organic body they do their work, and 

 new facts, if real facts, must be comprehended in the larger 

 dynamic system. Biology is now well launched out in the 

 attempt to find dynamic solutions to its problems, and mor- 

 phology including cell morphology still has contributions to make 

 to the attempt. It is difficult indeed to understand the struc- 

 ture of a mechanism without some knowledge of its function, 

 but it is equally difficult to appreciate a structureless function. 

 Of interest from the standpoint of chromosomal independence 

 are the observations now being carried on by Chambers on the 

 micro-dissection of the living cell. It appears from this work that 

 there is gradually being established from the living material a 

 confirmation of the general principles of cell structure and be- 

 havior as worked out on fixed preparations. The fact that 

 certain structures as polar radiations, are not visible in the living 

 cell and are present in fixed cells, perhaps due to injury or pre- 

 cipitation caused by the fixing process, is not an argument 

 against their significance since they occur constantly and in 

 precise relations to other structures. If not significant in them- 

 selves they are at least manifestations of processes which lie 

 more deeply in the cell. Of particular interest here is the 

 observation as yet unpublished of Dr. Chambers, of which he 

 kindly permits mention to be made here, that in grasshopper 

 spermatocytes the telophasic chromosomes are to be found in the 

 vesicular condition. When single grasshopper chromosomes are 

 removed and allowed to grow in plasma they develop into round 



