REPAIRS AND REGENERATION 107 



large, basket-like gill, provided with an entrance 

 and an exit for the water. 



To this succeeds a small connecting body por- 

 tion which contains part of the intestines and 

 finally there is the so-called intestine-sac with 

 stomach, intestine, heart, reproductive organs, etc. 

 If we divide the body of a clavellina at the level 

 of the connecting portion, so that the gill-basket 

 and the intestinal-sac are separated from one 

 another, either or both of these two portions can 

 in three or four days complete itself into an entire 

 organism, since by means of true regeneration pro- 

 ceeding from the incision, the gill-basket makes 

 itself an intestinal -sac and the intestinal-sac a gill- 

 basket. 



With this process we have already become 

 familiar, for it is the kind of thing which we have 

 studied in the hydra and in the earth-worm, but 

 the process of reconstruction sometimes takes place 

 in quite a different manner, and this is especially 

 the case in smaller individuals. In these cases 

 reconstruction begins not by a process of renewal 

 but by one of regression. 



The organisation of the gill-basket, its ciliated 

 clefts, its openings, etc., all gradually dwindle away. 

 At the end of five or six days no more organisation 

 is to be seen in these parts, which appear like white 

 spheres, in fact the describer states that when he 



