THE MONERON BECOMES A CELL. 345 



Only such homogeneous organisms as are yet not 

 differentiated, and are similar to inorganic crystals in 

 being homogeneously composed of one single substance, 

 could arise by spontaneous generation, and could become the 

 primaeval parents of all other organisms. In their further 

 development we have pointed out that the most important 

 process is the formation of a kernel or nucleus in the simple 

 little lump of albumen. We can conceive this to take place 

 in a purely physical manner, by the condensation of the 

 innermost central part of the albumen. The more solid 

 central mass, which at first gradually shaded ofl* into the 

 peripheral plasma, becomes sharply separated from it, and 

 thus forms an independent, round, albuminous corpuscle, 

 the kernel ; and by this process the Moneron becomes 

 a cell. Now, it must have become evident from our 

 previous chapters, that the further development of all 

 other organisms out of such a cell presents no difficulty, for 

 every animal and every plant, in the beginning of its indi- 

 vidual life, is a simple cell. Man, as well as every other 

 animal, is at first nothing but a simple «gg-cell, a single 

 lump of mucus, containing a kernel (p. 297, Fig. 5). 



In the same way as the kernel of the organic cell 

 arose in the interior or central mass of the originally homo- 

 geneous lump of plasma, by separation, so, too, the first cell- 

 Tnembrane was formed on its surface. This simple, but most 

 important process, as has already been remarked, can like- 

 wise be explained in a purely physical manner, either as a 

 chemical deposit, or as a physical condensation in the upper- 

 most stratum of the mass, or as a secretion. One of the first 

 processes of adaptation effected by the Moneron originating 

 by spontaneous generation must have been the condensation 



