268 



CHILD. 



[VOL. I. 



corresponding ventral furrow turns anteriorly a short distance 

 from the edge and meets the main furrow between a and c. 

 Thus the ventral surface of b is completely marked off from 

 other segments. Both the dorsal and ventral furrows between 

 b and a are rather shallow. The organs in b are distinctly 

 abnormal. A rather small ovary and vitellarium appear nearer 

 the edge than in normal segments, probably because of the 

 increasing length of the segment b nearer the edge. The 

 oviduct is incomplete and ends bluntly, as the figure indicates. 



FIG. 31. 



A distinct pore is present, and connected with it is a well- 

 developed cirrus, but no trace of a vas deferens is found any- 

 where in the segment. The position of the various organs 

 illustrates well the relation of each to the form of the segment 

 in the region where it occurs. Thus the ovary and vitellarium, 

 which appear from the dorsal surface to be near the posterior 

 edge of the segment, lie midway between the bounding furrows 

 on the ventral surface, and the oviduct, which extends some- 

 what dorsally from the ovary, runs obliquely forward towards 

 the edge, so that it is normally placed with regard to the fur- 

 rows on the dorsal surface. The pore lies near the anterior 

 end of the segment. The ventral furrow bounding b anteriorly 

 turns backward before reaching the edge and unites with the 



