THE DEGENERATED CELLS IN THE TESTIS OF 

 LEPTINOTARSA SIGNATICOLLISi 



H. L. WIEMAN 



University of Cincinnati 



Nine Figures 



The present contribution comprises a detailed account of a 

 peculiar process of degeneration or cytolysis of certain cells in the 

 testis of the chrysomelid beetle, Leptinotarsa signaticollis, the 

 occurrence of which was noted in a previous publication (Wie- 

 man, '10). Since then I have been able to study the process 

 more minutely, with the result that I can now give a more com- 

 plete account of its history. 



The testes are two in number and lie one on either side of the 

 body. Each testis of the imago consists of two disc-shaped 

 lobes bound together by a common sheath of epithelial cells. 

 Two ducts, one from the flattened proximal end of each lobe, 

 unite to form a common duct on either side which in turn unites 

 with its fellow from the other side to form the single median effer- 

 ent sperm duct (fig. 1). Each lobe, except in the region opposite 

 the point where the' duct leaves, i.e., the distal end, is divided into 

 follicles separated from each other by ingrowths of epithelial 

 cells from the investing sheath (the sheath has been omitted from 

 the figures for the sake of simplicity). The follicles, radiate 

 about the central cavity of the testis (which is continuous with 

 the cavity of the duct) much in the manner of the spokes of a 

 wheel about the hub. They contain cysts of germ cells in various 

 stages of development, while the central , cavity in the mature 

 organ is filled with spermatozoa. 



^ I take pleasure in acknowledging my obligation to Professor W. L. Tower of 

 the University of Chicago, to whom I am indebted for the material upon which 

 the present study was based. 



JOUBNAIi OF MOBPHOLOGT, VoL. 21, No. 4. 



