214 \VINTERTON C. CURTIS. 



/. e., whether \ve had not to do with what one might term pseudo- 

 proglottids as distinguished from the true or posterior proglottids. 

 This led me to consider the criterion by which one would deter- 

 mine whether a region of the body was a proglottid or not. My 

 view is that we are justified in applying the name proglottid to 

 any region of the body which is set off from the neighboring 

 parts by constrictions and which contains a complete set of repro- 

 ductive organs. From many specimens which were examined 

 when the non-segmented zone was almost obliterated, I found as 

 previously stated that no specimens observed showed less than 

 30 + segments of "anterior" origin and that the number pro- 

 duced in this region was 50 -f in the majority of cases. If this is 

 so, specimens like Figs. 15, PI. VI., and 21, PI. VII., show us 

 that such "anterior" proglottids may eventually become sexually 

 mature and be shed off the same as any other in the chain. More- 

 over, as will be seen in the two figures just cited, anterior pro- 

 glottids thus becoming ripe change their shape by the flattening of 

 the four-pointed lappets of the earlier stage and assume exactly 

 the shape characteristic for a ripe proglottid of posterior origin. 

 I think, therefore, that we may dispose of any question as to 

 whether the segments originating from in front backwards are to 

 be considered as true proglottids. 



The new segmentation appearing at either end of the neck re- 

 gion is identical with that which occurs in the young worm save 

 that the "anterior" proglottids begin to appear before so many 

 of the posterior ones have been developed. Were it not for the 

 single terminal segment and for the slightly greater size of the 

 bothria on the scolex one would certainly class specimens like 

 Figs. 22 and 24, PI. VII., as young worms similar to those shown 

 in Figs. 7 and 10, PI. IV., and 1 1, of PI. V. The size of the bothria 

 would not be very reliable in preserved specimens, but the single 

 terminal proglottid with its four-pointed lappets would seem un- 

 questionably to be the first anterior proglottid of a preceding 

 strobilla. 



I have not been able to secure stages showing that the seg- 

 mentation of the neck region finally results in a new strobilla. 

 The difficulty in distinguishing specimens, which have passed far- 

 ther along the way to this condition than Fig. 24, from stages in 



