504 F. A. E. CREW AND HONOR B. FELL 



Thoso show distinct nuclei, and the outhnos of the cytoplasm, 

 though irregular, are distinguishable. 



The centre of the lumen is occupied by an aggregation of cells 

 surrounding a circular body composed of two concentric rings 

 and a darker central area. The investing cells show two distinct 

 layers : an outer layer in which the nuclei are visible, and 

 an inner layer presenting no cell structure whatexer. This 

 inner layer might be regarded as part of the central body 

 which it closely resembles both in general structure and staining 

 reaction. Though of an asymmetrical contour which corre- 

 sponds with that of the outer layer, it displays none of the 

 angularities of the latter. The appearance suggests that during 

 life surface tension was causing it gradually to assume a 

 spherical shape. 



(5) (PL 18, fig. 4) This section was stained with Mallory's 

 stain and a coloured dra^\^ng has been made to show the 

 somewhat remarkable staining reaction. A single circular 

 body of rather small size is present in a seminiferous tubule. 

 The body consists of a whitish central area surrounded by 

 a bright blue ring. A circle of more darkly-stained granules 

 is present. The body is suiTounded by a large mass of debris 

 which on one side spreads out into a syncitium connecting 

 the central structure with the wall of the tubule, and on the 

 other side is condensing into a narrower more deei^ly-stained 

 layer. There is a sharp line of demarcation between the body 

 and the surromiding protoplasm which stains an orange bro'VN'n. 

 The epithelial cells are arranged in the usual single degenerate 

 layer applied to the basement membrane. 



Discussion. — From a study of the series of specimens 

 which have been described above it would appear that the 

 process of formation of these remarkable bodies is somewhat 

 as follows : 



In the seminiferous tubules we have seen that degeneration 

 spreads from the centre towards the periphery. The chief 

 factor in this degeneration seems to be a gradual softening 

 of the protoplasm of the epithelial cells. As this softening 

 increases, the innermost cells can no longer adhere to the 



