84 T. B, ROSSETER OX THE GEXITAL ORGAXS OF TAENIA SIKUOSA. 



cell itself, being structureless, remains in a perfectly hyaline 

 condition. Ordinarily this spatulate head of the spermatozoon 

 wraps itself round until if forms a blunt-pointed spathe 

 (Fig. 2, b), and this no doubt is its normal condition when it 

 meets and penetrates the ovum in the fructifying canal. 



On leaving the testis the vasa-efferentia curves sharply but 

 gracefully upwards, and becomes a sinuous vas-deferens (Fig. 1, 6), 

 run nin g distally and proximally in the segment, and ultimately 

 becomes a sac within the vesicula seminalis. In young specimens 

 this sac is very pronounced, and may be beautifully demonstrated 

 by the aid of haemalum. 



The vesicula seminalis (Fig. 1, c) is situated in the dorso -anterior 

 portion of the proglottis. Its distal end is rounded, whilst its 

 proximal end elongates itself to form the cirrus-sheath. It is an 

 elongated pyriform sac, "35 mm. in length and "065 in breadth. 



The cirrus-sheath is, normally, '13 mm. in length, but during 

 the act of coition it exserts itself to *212 mm. Its mean width is 

 '016 mm. Externally it is hispid, but internally it is smooth. 

 The cirrus (Fig 1, e) is a long, hollow, smooth, diaphanous, flexible 

 tube, and, when exserted for the purpose of coition, has a length 

 of "23 mm., and is 2 /x wide. 



Below the male genital pore, somewhat anterior of the plane 

 of the cirrus-pouch, is what, under a low power, appears to be a 

 dark punctate spot or point. This is not seen in the early or 

 young proglottides, but makes its appearance as the male organ 

 approaches maturity, and continues to increase in size until the 

 male organ has attained its perfection. Seen under a ^-inch 

 objective it is a globular spinous sac (Fig. l,f), with a round, 

 smooth, diaphanous collar, somewhat similar to a collared monad. 

 It is hollow, and the endoderm is smooth,, although punctate. 

 These punctuations are at the bases of the spines. In some 

 proglottides it appears as if the cirrus with the proximal end of 

 its sheath passes through its centre. Such, however, is not the 

 case, for it lies dorsal of that organ, and is easily dissociated, by 

 teasing, from the cellular tissue in which it is embedded. 



One cannot refer with any certainty farther back than Dujardin 

 respecting the knowledge of the existence of this spinous body 



