THE WONDERS OF LIFE 



Hence they behave within the plant-cell just like the 

 free-living chromacea in the water. On the strength of 

 this significant comparison, one of our ablest and most 

 open-minded scientists, Fritz Muller-Desterro, of Brazil, 

 pointed out in 1893 that we may see in every green 

 vegetal cell a symbiosis between plasmodomous green 

 and plasmophagous not - green companions {cf. my 

 Anthropogeny, figs. 277 and 278, and in the text). 



Many species of the simplest chromacea live as 

 monobia (individually). When the tiny plasma globules 

 have split into two equal halves by simple segmentation, 

 they separate, and live their lives apart. This is the 

 case with the common, ubiquitous chroococcus. How- 

 ever, most species live in common, the plasma granules 

 forming more or less thick coenobia, or communities or 

 colonies of cells. In the simplest case (aphanocapsa) the 

 social cytodes secrete a structureless gelatinous mass, in 

 which numbers of blue-green plasma globules are irregu- 

 larly distributed. In the glceocapsa, which forms a thin 

 blue-green gelatinous deposit on damp walls and rocks, 

 the constituent cytodes cover themselves immediately 

 after cleavage with a fresh gelatinous envelope, and these 

 run together into large masses. But the majority of the 

 chromacea form firm, threadlike cell communities or 

 chains of plastids (catenal coenobia.) As the transverse 

 cleavage of the rapidly multiplying cytodes always 

 follows the same direction, and the new daughter-cytodes 

 remain joined at the cleavage surfaces, and are flattened 

 into discoid shape, we get stringlike formations or 

 articulated threads of considerable length, as in the 

 oscillaria and nostochina. When a number of these 

 threads are joined together in gelatinous masses, we 

 often get large, irregular, jelly-like bodies, as in the 

 common " shooting - star jellies" (nostoc communis). 

 They attain the size of a plum. 



In view of the extreme importance which I attach to 



196 



