496 C. M. Child. 



regeneration of many specimens in which these ducts were of large 

 size and filled with the sexual products was observed and it was 

 found that the regeneration of these structures was as complete in 

 the absence of the ganglia as when they were present, though 

 usually somewhat less rapid. The following case will serve as an 

 example: A specimen in the height of sexual activity was cut as 

 in Fig. 28 through the anterior end of the pharynx and again 

 somewhat posterior to the middle of the pharynx, the piece be- 

 tween the two cuts being used for experiment. It will be observed 

 that this piece contained only the anterior portion of the vasa 

 deferentia and a part of the uterus. In Fig. 29 the condition 

 of the piece seventeen days after section is indicated. At this 

 time the ducts were extending into the new tissue but the amount 

 of their regeneration was not clearly visible. Sixty-five days after 

 section the piece presented the appearance of Fig. 30. Com- 

 plete regeneration of the ducts and the terminal organs had taken 

 place and the ducts were widely distended by sexual products. 

 Similar results were obtained in other cases where the animals 

 used were in a condition of sexual activity. The piece just 

 described was without ganglia, but in other pieces with ganglia 

 the result was the same, though it occurred in a somewhat shorter 

 time. 



When nearly all of the body was removed from breeding speci- 

 mens, 7. e., when regeneration occurred from a level only slightly 

 posterior to the ganglia, nothing more than a small genital area, 

 as in Figs. 10 or 11, was ever regenerated even though the 

 ganglia were present. There can be little doubt, I think, that the 

 complete regeneration of the ducts and terminal organs of large 

 size in the case just described was due first to the fact that parts of 

 the ducts remained in the old tissue, and second, and probably 

 chiefly, to the fact that the ducts were in an active functional con- 

 dition, I. e.^ filled with sexual products. Here again, as in the 

 case of the intestine, the possible effect of the pressure of the con- 

 tents of the ducts upon the walls and of other functional condi- 

 tions upon regeneration must be taken into account. In my 

 opinion these are important factors. In the cases where all parts 

 of the ducts were removed and thus the question as to the effect 



