22O CHILD. [VOL. I. 



The figures all represent cases of partial division of segments, 

 together with the accompanying abnormalities in the form and 

 position of the genital organs. A classification is difficult, and, 

 I think, unnecessary. In general the more simple and regular 

 cases are discussed first, the complex ones later. Cases resem- 

 bling each other are grouped together as far as possible. 



Figs. 2-6 are taken from various points near the anterior 

 end of the chain. They all show stages before the appearance 

 of the genital organs. These cases, although differing somewhat 

 in form, are grouped together here as furnishing some evidence 

 for the conclusion that the abnormalities of this kind appear at 

 the time the furrows are formed and are not due to a later divi- 

 sion of proglottids. They are certainly as common in these 

 earlier stages as in later ones. Following these are grouped 

 the cases in which the furrows on the two surfaces correspond 

 closely. These include Figs. 7-15, as well as Figs. 2, 3, 5, and 

 6 of the preceding group. In Figs. 7-15 the genital organs, 

 though they may be abnormal in position, are nearly always 

 fully developed. The remaining figures, 16-23, show cases 

 which are more complex and in which the furrows on the two 

 surfaces do not usually correspond. Moreover, in these cases 

 some of the genital organs are commonly rudimentary or abnor- 

 mally developed. 



Figure 2. 



This figure was taken from the extreme anterior end of the 

 body. The furrows between the proglottids have become fairly 



distinct. As the dorsal and ventral fur- 

 rows correspond exactly in position, only 

 one surface is represented in the figure. 

 Four abnormal segments, a, b, c, and d, 

 are present. The segments a and b are 

 both examples of partial division, one upon 

 the right side, the other on the left. Here 



the partial furrows end free, not far from the middle of the seg- 

 ment in which they occur, so that the proglottid appears as if 

 partially split from one edge. The two cases at the anterior 



