PHYSIOLOGY OF REGENERATION 



19 



have availed myself of an opportunity to investigate this factor 

 when a number of specimens were found at the breeding season 

 whose sex could readily be distinguished by the presence of eggs 

 or of sperms within the body. Twenty worms of each sex were 

 cut in two about the middle of the body, and left to regenerate 

 new tails. As will be seen from table 9, both the males and the 

 females regenerated from 4 to 9 segments in two weeks, and from 5 

 to 10 segments in twenty days. It is quite evident from this that 

 the sex of the animal has no influence upon its regenerative power, 

 and this factor, though not considered in earlier experiments 

 ('09b), probably had no effect upon the results. 



D. RELATION OF THE AMOUNT OF REMOVED TO THE AMOUNT 

 OF REGENERATED TISSUE 



In a previous publication (Morguhs '09b) it was maintained 

 that in Podarke the regenerated tail does not reach its original 

 length when it grows from about the middle of the body, although 

 the full number of lost segments is usually restored when only a 

 small part of the tail has been detached. About the same time 

 a paper was published (Ellis, '09) in which this matter of the rela- 

 tion between the amount of removed and of regenerated tissue 

 was treated more fully, the results leading to a similar conclu- 

 sion, that "regeneration ceases before the part removed has been 

 completely regenerated" (p. 444). 



Since I stated the matter at first more as an opinion than as a 

 fact, I have now undertaken to verify the conclusion by a special 

 experiment in which record has been kept of both the removed 



TABLE 10 



