The General Infections of the Genital Organs of Cattle 363 



cal line, the nuclear membrane. The nucleus, of full oval 

 contour except at its base, occupies normally a little more 

 than one-third of the basal area of the head. Its sides con- 

 form to the general contour of the cell membrane. The 

 chromasomic material does not occur in this cell as definite 

 granules, but is disseminated throughout the nucleus. The 

 nuclear element in a healthy cell takes a basic stain, and 

 when stained with methylene blue appears very slightly 

 granular and darker than the cytoplasmic portion. 



The cytoplasmic portion of the head, anteriorly and later- 

 ally, corresponds in contour with the general oval outline of 

 the cell membrane. Caudally, it lies against the nucleus, 

 whose convex face is directed into the base of the cytoplasm, 

 forming a shallow cup or fovea in the latter. The cytoplasm 

 of the head takes carbol-fuchsin very faintly, which, when 

 counterstained with methylene blue, is entirely replaced by 

 the latter. 



The neck parts in the bovine spermatozoon are very small 

 and not defined except under a very high magnification. In 

 the human spermatozoon two neck granules are described. 

 In spermatogenesis they arise from a single granule, which 

 in the last stages of development divides. One granule 

 passes to the caudal end of the neck and remains there in 

 close relation to the connecting piece or body ; the other 

 granule passes to the anterior end to become fused with the 

 base of the head. If such separation of the neck granules 

 occurs in the bovine spermatozoon, it is not brought out by 

 my present method of staining. The neck granule appears 

 as a single bar, fused to the base of the head. Apparently 

 there is a slight concavity at the base, into which the neck 

 is inserted, obscuring most of it from view. The granule, 

 fused into this concavity, appears therefore to be located 

 within the nuclear material; this is undoubtedly never the 

 case. Aside from this granule, the neck remains unstained 

 under the methods which I have employed. 



By the embryologist it is held that, when fecundation 

 takes place, the sperm head enters the cell membrane of the 

 ovum. The sperm then loses its tail, which separates be- 



