264 CHILD. [VOL. I. 



mally, but at the left there are three segments and at the right 

 only two, and a corresponding number of sets of genital 

 organs is found. 



Figure 2J. 



A spiral furrow making only a little more than half a turn 

 appears in this case. At the left the upper surface of a is 

 united at the edge with the lower surface of b, and at the right 



the lower surface of a unites at the 

 edge with the upper surface of b. ' 



The only abnormality visible at 

 this stage in the genital organs ap- 

 pears at the left in a. Here the 



genital " Anlage " is elongated and narrower than in the other 

 cases. The proglottid is not sufficiently developed to show the 

 ducts and pores, so that it is impossible to determine just what 

 the situation of these organs will be. 



Figure 28. 



Here the natural relation of the dorsal and ventral surface is 

 somewhat altered. The figure is drawn with the dorsal surface 

 uppermost, and it is seen that the furrows on the dorsal surface 

 lie further posteriorly than those corresponding to them on the 

 ventral surface. The furrows bounding a posteriorly do not 

 meet at the edge, as they would if normal and merely distorted 

 by pressure or otherwise, but the end of the ventral furrow is 

 anterior to the dorsal. The furrows d and d' would correspond 

 to each other if normal, but as a matter of fact d' meets c at the 

 left edge instead of meeting with its corresponding furrow d, 

 thus producing a slight spiral. The furrows e and c' would 

 meet at the two edges if normal, but here again the ventral 

 furrow is considerably anterior to the dorsal except at the 

 right edge, and its left end shows no indication of bending 

 posteriorly to meet the latter. A somewhat similar condition 

 is seen frequently in mounted specimens, but in most cases 

 is simply a distortion due to the compression between glass 

 plates during fixation. The real abnormalities such as occur 



