22O WINTERTON C. CURTIS. 



tained by some to the present day, having been defended more 

 recently by J. v. Kennel in his " Lehrbuch der Zoologie." On 

 the other hand it has been subject to considerable attack which 

 is summarized in the theory accepted by Lang and Korschelt 

 and Heider. The latter authors hold that the scolex and a single 

 proglottid represent the individual and are equal to the body of 

 a trematode and that the present organization of the cestode 

 body has been attained by the reduplication of that region which 

 contains the reproductive organs. In a way this opinion is not 

 so different from the other view since we may think of this 

 reduplication as a budding process in which only the posterior 

 half of the individual is formed. 



Broadly speaking, the discussion reduces itself to the question 

 whether we shall consider the segmented condition of the ces- 

 tode as having arisen by the loss of individuality and the adhe- 

 rence together of originally complete individuals which were 

 formed by budding, or as arisen by the elongation and redupli- 

 cation of certain parts in a single individual. It is like the ques- 

 tion of metamerism which though most commonly explained in 

 accordance with the latter (Lang, '82, and others) has neverthe- 

 less been accounted for by some (Whitman, '99) along the line 

 of the former view. Personally, I agree entirely with Braun in 

 the concluding paragraph of the discussion above cited, that the 

 theory one will incline to is largely a question of temperament 

 since the phenomena can be interpreted in either way. The 

 facts brought out for C. laciniatum, while they show a new 

 method of proglottid formation do not turn the scale in favor of 

 either interpretation. If such a condition as is here described 

 could be shown to be more widespread in the cestoda and thus 

 the one we now regard as primitive should lose some of its 

 importance we might then believe that a segmentation proceed- 

 ing from both ends toward the middle is better explained upon 

 the hypothesis that reduplication of parts has occurred in a single 

 individual than upon the theory that it has arisen through a 

 process of strobillization identical with that by which the ephyrae 

 of a scyphozoan are formed. But the facts regarding C. lacinia- 

 tum stand alone and we can at present claim no more than that the 

 formation of proglottids in the cestoda deserves renewed investi- 



