•102 



F. Jl. Krecker, 



regeiierate begiiining at tlie 14tli soniite biit it had not yet touched 

 the body wall and no regeneration of the latter Lad occured. Nine 

 days later those that were alive liad several new somites. 



For these experiments with the intestina almost 500 worms were 

 uscd and the results were similar to those given above. The data of 

 the experiments which have just been described are sunimarized in 

 the following table 



Table. 



The figures in the columns under "No contact and no regenera- 

 tion" indicate the number of individuals alive and without regeneration 

 of the body wall at the end of the Ist, 2nd, and 4tli weeks respectiv- 

 ely. No individiial is coiinted twice. The total of each horizontal 

 row is equal to the number of individuals used in the corresponding 

 series. 



The records cited show that of 87 individuals operated upon 59 

 lived and that in 40, or nearly 75 per cent, of these the intestina was 

 not in contact with the body wall at the posterior end and no regene- 

 ration of the body wall had occured during periods varying from one 

 to four weeks. Twenty-four had shoAvn no signs of a posterior regene- 

 ration of the body wall at the end of one week, the sanie was true of 

 twelve at the end of two weeks and of four at the end of four weeks. 

 Furthermore of these 40 individuals, twelve had regenerated from one- 

 half to two Segments of the intestine alone within two weeks, four had 

 regenerated it within three weeks and three had done so in four weeks. 



1 No regeneration in one. 



