389] ANOPLOCEPHALIDJE—DOUTHITT 39 



vesicula persist to the last either in situ or crowded to one side. The 

 receptacuhim persists as a mere vestige. The shell gland persists as a 

 structureless mass connected with the receptaculum and with the pos- 

 terior end of the proglottid by a narrow bridge, such as has been de- 

 scribed for Moniezia carrinoi and some of its relatives. All the other 

 organs are reabsorbed, the testes being the last to give way. The pro- 

 glottid becomes little more than a thin-walled egg capsule, the cortical 

 layer being reduced sometimes to a thickness of 20/x. 



The uteri of the three species of Schizotaenia here described agree 

 in all essential respects but differ decidedly from the account presented 

 by von Janicki (1906) for S. hagmanni which is accepted as the type 

 of the genus. He recognized nothing comparable to the degenerate 

 reticulum or diffuse uterus described here ; also the three species de- 

 scribed here show nothing comparable to the "ausserst feinen Schlitze, 

 der als mannigfach gewellte Flache durch den grossten Teil der Mark- 

 schicht ***** sich hinzieht". Von Janicki does not figure this 

 structure except in transverse section, in which way it gives very little 

 information. In view however of the fact that such a structure would 

 not be greatly different in appearance from that of the degenerate retic- 

 ulum described here, I am inclined to believe the difference is one of 

 interpretation rather than structure. Likewise von Janicki 's drawings 

 of the " Spaltenwerk " (Figs. 85, 86) resemble closely the condition 

 observed in frontal sections of the early saccular stage when the thin 

 uterus is applied to the uneven surface of the ovary and only parts 

 of the cavity appear in each section. There is no ground therefore 

 for considering these uteri as differing fundamentally in this regard. 

 The possession of uterine outpocketings by the present species is strik- 

 ing and is significant as to its relationships ; but the fact offers no 

 barrier to its inclusion in the genus Schizotaenia; it is what should be 

 expected in the more primitive members of the genus. 



The uterine embryos have three membranes. The outer is spherical 

 and 30 to 40/a in diameter. The middle is loose-fitting and irregular. 

 The diameter of the embryo is 10 to 17 )i with no considerable range of 

 variation in any one individual. There is a perfectly developed pyri- 

 form apparatus whose length plus that of the embryo is 16 to 26/a. The 

 two stout tapering horns cross at the tip and extend backwards as 

 long, slender processes. 



The excretory ducts lies in about the same dorso ventral plane, the 

 originally dorsal duct outside. This arrangement is present in both 

 strobila and scolex. The path across the proglottid is a curve. The 

 dorsal duct is usually between 10 and 12/x, in diameter at the ends of 

 the proglottids, narrowing in the middle to 6 or 7/x, on the side away 



