THE BEGINNINGS OF LIFE. 407 



We shall subsequently have occasion to refer to other 

 series of changes in which as in thess embryonal 

 spheres and in the embryonal areas of the pellicle 

 the portions of matter undergoing metamorphosis., may 

 either segment into one or other of various lower 

 forms of life, or may each be transformed bodily into 

 a single large organism. 



Some remarkable transformations have also been ob- 

 served taking place in individual chlorophyll corpuscles 

 which still remained in situ within the filament. A 

 careful examination of these chlorophyll corpuscles soon 

 suffices to convince the observer that they are veritable 

 independent units. They grow, in fact, and frequently 

 undergo spontaneous division after the fashion of an 

 algoid corpuscle or gonidium, as Nageli long ago ascer- 

 tained. It is not at all uncommon to see some of 

 the corpuscles within dying filaments of Nitella become 

 of a bright grass-green colour and increase very much 

 in size, growing more or less ovoid or irregular in 

 shape, and exhibiting certain irregular markings in 

 their interior. The later modifications which cor- 

 puscles affected -in this particular manner undergo 

 have not been ascertained, though changes of a dif- 

 ferent nature have been followed out much more 

 completely. 



An uninjured Nitella internode, two and a half inches 

 in length, had been placed with some water in a corked 

 test-tube. It retained its vitality for a long time, 



