2IO THE BEGINNINGS OF IIFE. 



Many variations exist in the character of these areas 

 in different cases, some of which I will now attempt 

 to describe, as I have lately had an opportunity of 

 watching numerous transitional conditions. 



The pellicle which formed on a filtered maceration 

 of hay during frosty weather (when the temperature of 

 the room in which the infusion was kept was rarely 

 above 55° F, and sometimes rather lower than this) pre- 

 sented changes of a most instructive character. On the 

 third and fourth days the pellicle was still thin, although 

 on microscopical examination all portions of it were 

 found to be thickly dotted with embryonal areas. 

 Nearly all of them were very small, though a few areas 

 of medium size were intermixed ^ The smallest were 

 not more than 4 oVo" of an inch in diameter, and these 

 separated themselves from the pellicle as single cor- 

 puscles; slightly larger areas broke up into two or three 

 corpuscles ; and others, larger still, into 4-10 corpuscles. 

 In most of these small areas, the corpuscles were formed 

 with scarcely any appreciable alteration in the refractive 

 index of the matter of which they were composed : this 

 simply became individualized, so that the corpuscles 

 separated from the surrounding pellicle and from their 

 fellows, still presenting all the appearance of being por- 

 tions of the pellicle, and exhibiting from 4-10 altered 

 Bacteria in their substance. In some cases the products 

 of segmentation soon developed into actual flagellated 



^ In these medium-sized areas segmentation was accompanied by the 

 production of homogeneous and highly refractive protoplasm. 



