REPRODUCTION 109 



body. But this experiment (and many others 

 of a similar kind might be cited) seems to show 

 that the nuclei of the various cells during 

 development, at any rate, have no specific 

 character, but are capable, to put the matter 

 colloquially, of turning their hands to any job 

 in the gradually rising edifice of the body. 



A third and final experiment may be quoted, 

 of quite a different character. It was also car- 

 ried out by Wilson and is corroborated by 

 other and similar experiments on other forms. 



There is a little creature which lives inAmphioxus 

 certain seas and is known as the Lancelet. To 

 scientific men, and now indeed to numbers of 

 readers who would not claim to be scientific, 

 this creature is better known as the Amphioxus. 

 In the course of its development the single cell 

 of which it was originally formed divides 

 into two-, four-, eight-, sixteen-celled stages. 



Now let us suppose that at the eight-celled 

 stage the group is put into a test-tube with 

 water and violently shaken. The result is that 

 the eight cells are shaken apart and become 

 completely separated from one another. Then 

 a very remarkable thing happens. Most people 

 would imagine that the immature creature 

 must have been killed by such rough treatment, 

 but such is not the case. Each of the eight 

 cells, undaunted by what ii has been through, 



