THE BEGINNINGS OF LIFE. 241 



place was that the granules, which had been at first 

 more densely aggregated towards the centre, dissemi- 

 nated themselves uniformly through the ovum — whilst 

 at the same time the simple clear zone thickened 

 into a distinct membrane. At this stage the whole egg 

 appeared somewhat lighter and more transparent than 

 the surrounding pellicle. Soon after this — differentia- 

 tion still proceeding — the mass of enclosed granules 

 gradually became converted into a real embryo, which 

 manifested its existence by slow movements — at first by 

 simple oscillations in the mass of granules, and then by 

 regular uniform movements of revolution of the whole 

 contents within its enveloping membrane, similar to 

 those of many other embryos. The slightest shock at 

 this stage immediately arrested the gyration. Then, 

 after a time, a pale spot appeared amongst the granules 

 in some part of the embryo, the alternate contraction 

 and dilatation of which soon showed that it was the 

 contractile vesicle of the infusorium. After a time the 

 embryo began to exhibit movements of quite a different 

 kind — sudden and irregular — no longer checked, but 

 rather increased by slight shocks from without. In 

 one of these sudden plunges the thin enveloping mem- 

 brane was ruptured, and there entered into the aquatic 

 world a free-swimming and ciliated infusorial animal- 

 cule having the characteristics of the species above 

 mentioned. 



Such is the marvellous story, and the description of 

 other observers is substantially similar. In the particular 



VOL. II. R 



