406 F. H. Kiecker, 



its great diameter and the firmer character of its tissues enabling 

 the intestine to be removed with ease. Experiments on this form 

 were also desirable in view of Morgan's results regarding the corre- 

 lation between the nervous System and regeneration in AUolobopJwra 

 foetida. Froni this work it seemed evident that there could be at least 

 some regeneration without the presence of a digestive tract in the new 

 portion but Morgan was uncertain regarding the role played by the 

 digestive tract. His conckisions on this point are as follows. "Whether 

 the presence or absence of a digestive tract in the new part depends 

 upon whether or not the old digestive tract was injured on its ventral 

 side can only be determined by further experiments. That it may be 

 injured is certain; that it is sometimes not injured, or at least not cut, 

 I can also State to be true." 



The following records are taken from experiments performed to 

 gain more light on these points. 



Ist Series — May lOtli 08. The first seven somites were cut off 

 and some of the ahmentary tract was then removed from the part 

 remaining. Four individuals were used. On June 24th three of these 

 showed no signs of regeneration but sections revealed the fact that the 

 tip of the nerve cord liad been cut so that it did not touch the cut 

 surface of the body wall. A layer of epidermis had grown over and 

 completely closed the wound but there was Jio further growtli. The 

 fourth individual had a short pointed tongue of tissue in which there 

 was no digestive tract. The nerve had not been injured. 



2nd Series — Sept. 29th 08. From five specimens the first seven 

 somites were cut off and the intestine was removed as before. By 

 Nov. 6tli all had a short tongue of new tissue in which there was no 

 intestine. Several Worms from which an equal number of somites had 

 been cut without the subsequent removal of the digestive tract were 

 used as a control. In the same length of time these worms had a con- 

 siderably longer tongue than had the others and its segmentation was 

 clearly indicated. An alimentary tract was of course present. 



3rd Series — Jan. 23rd 09. The first six somites were cut off from 

 ten Worms and then a portion of the alimentary tract was dj'awn out. 

 On Feb. 27th of the eight individuals that were still alive all had a short 

 pointed tongue of new tissue, the digestive tract not being present. 



From the second and the third series it is evident that a certain 

 amount of regeneration of the body wall is possible in Lumhricus even 

 when the intestine is absent. Furthermore, from the fact that no 

 digestive tract was found in the new portion one can conclude that it 



