FORMATION OF PROGLOTTIDS IN CROSSOBOTHRIUM. 205 



Oti page 1597, Kuchenmeister, von Siebold, Lewald, Haubner 

 and Leuckart are quoted as having studied this stage of the de- 

 velopment in a number of forms about 1850, since which very 

 little attention has been paid to it. Leuckart's first work upon 

 this point appeared in 1856 and was subsequently elaborated in 

 the editions of his text-book. 



On p. 1600, Braun says : " Die naheren Vorgange bei der 

 Bildung der Proglottiden sind uns bisher noch ganz unbekannt, 

 nur die Anlage und Entwickelung der Genitalien ist bei manchen 

 Arten erforscht." 



From indirect references at other places in the volume it is 

 clear that the accounts current in our text-books are justified by 

 the absence of any published description contradicting the accepted 

 method of proglottid formation. 



The amount of literature published on Cestodes up to 1896 is 

 enormous, but the manner of proglottid formation was established 

 and had been explicitly described for so long a time before this 

 date that one can hardly believe any marked exception to the 

 universal method could have escaped the notice and comment of 

 so thorough a reviewer as the author of this monograph has 

 shown himself to be. Upon such a point as this I feel that Braun 

 maybe taken as reliable and that I am justified in the conclusion 

 that no such process of proglottid formation was described previous 

 to 1896. 



I have consulted a considerable amount of the literature on 

 Cestoda appearing since that date, at first hand, and have cov 

 ered the abstracts and titles of cestode papers as they appear in 

 the Zodlogisclic Jalircsbcriclit, without finding anything to indi- 

 cate that accounts have been published of a method of proglottid 

 formation other than the one commonly accepted as the universal. 



Papers upon other phases of the proglottid question have 

 appeared, as for example one by Liihe, '98, who, in his exami- 

 nation of the segmentation of Ligula, found that the segments 

 which occur at the anterior end do not correspond to the arrange- 

 ment of the genitalia where these occur toward the posterior end 

 of the segmented area and hence, that this case is not one of true 

 proglottid formation but rather, to be considered as a differenti- 

 ation of another sort. While there may be some homology 



