108 WHAT IS LIFE 



first saw this condition he came to the conclusion 

 that the clavellina was either dead or on the way 

 to death. It was not so, however, for though the 

 creature remains or may remain in this condition 

 for two or three weeks, at last the day comes when 

 it begins to clear and to stretch and then after the 

 end of two or three days it is found that amorphous 

 mass has once more become a complete ascidian 

 with gill-basket and intestinal sac. It has become 

 a perfectly new organism which has no continuity 

 with the parts of the earlier organisation though 

 it has with its material. Its gill-basket is not a 

 derivative of the old one ; it is very much smaller 

 and has fewer and smaller openings. What has 

 happened is that the old organised gill-basket has 

 returned to an indifferent substance and then, from 

 this indifferent substance on embryological lines, 

 a new smaller individual has been constituted. But 

 this is not the whole story, for it is not merely the 

 isolated gill-basket which can restore itself by 

 means of this roundabout process, but after having 

 isolated the basket, it can be itself divided either 

 into an upper and lower portion or into an anterior 

 and a posterior bit and each of these portions will 

 then go through the same process, that is each of 

 them will first of all return to the indifferent con- 

 dition and then from that re-constitute itself into 

 a new small ascidian. 



