No. 6.] THE CESTODE MONIEZIA EXPANSA. 



Figure 40. 



289 



Two cases of partial division are figured here as seen from 

 the dorsal surface. The two are almost exactly similar, except 

 that in one case the partial furrows extend from the left edge, in 

 the other from the right. At the side of the body, which is 

 completely divided in each case, two complete sets of genital 

 organs normally situated are found. At the other side the 

 inner portions are double, but the ducts unite to form a single 



FIG. 41. 



vas deferens and a single oviduct, and these open through a 

 single pore, which is situated almost exactly in the middle of 

 the undivided edge. The most remarkable fact is that the 

 position of the anterior set is the reverse of that of the 

 posterior set in each case, the oviduct running posteriorly from 

 the ovary, and the vitellarium lying anterior instead of posterior 

 to the ovary. The vas deferens also runs posteriorly instead of 

 laterally. The arrangement of the organs is very evidently cor- 

 related with the incomplete separation of a and b and of c and d. 

 The undivided edges of a b and c d are shorter than the divided 

 edges, but the undivided edge of a b is longer than the un- 

 divided edge of c d, and it is interesting to note that in the 

 region corresponding to b of the edge a b a second pore appears, 



