2/8 R. PEARL AND M. R. CURTIS. 



No Graaffian follicles or Pfliiger's tubes were found, though 

 series of sections from all parts of the gonad were examined. 

 The general histological structure of the organ was such as to 

 indicate that it was in a degenerating condition at the time the 

 bird was killed. This process of degeneration had gone so far 

 that nothing like normal ovarian tissue was to be found. Whether 

 at any time in the life of the bird any part or all of the ovary had 

 been normal in structure, it is impossible now to say. The con- 

 dition of the gland at death afforded no certain evidence either for 

 or against this view. That oogenesis, however, could not have 

 gone beyond early stages during the later life of the bird is made 

 probable by the fact that it did not lay (except for the single doubt- 

 ful egg noted on p. 272), although possessed of a normal oviduct. 



The net result of the microscopical examination of the left 

 genital gland, which had the normal anatomical relations of an 

 ovary, is negative. 



HISTOLOGY OF THE RIGHT GENITAL GLAND (TESTIS). 



The limiting membrane of the right genital gland was not very 

 thick and was poorly preserved in our sections. Such parts of 

 it as were intact seemed to have a cellular outer layer with a 

 fibrous inner layer. We could not be sure of futher histological 

 details nor could we determine the extent of this tunic. 



The gland contained no normal seminiferous tubules but 

 showed evidence of tubular origin. The central portion was 

 more dense than the periphery and in this more dense portion a 

 few places showed the cells arranged as if small cellular rods 

 had been cut in various planes. These rods might be considered 

 tubes without lumen. They were formed by a single layer of 

 nearly cubical cells, about the size and form of the epithelial cells 

 of the seminiferous tubules at the age when these form a single 

 layer nearly filling the lumen. Around these rods was a thin 

 layer of fibrous tissue. Between the dense central portion and 

 the periphery the epithelial cells gradually disappeared so that 

 the greater portion of the gland appeared to be a connective 

 tissue skeleton representing the basal membranes of the tubes ( 

 and the intertubular stroma of the young gland. Most of the 

 tubes formed by the remaining basal membranes contained a few 



