386 INDIVIDUALITY OF CELLS 



that we are using analogy, but an interesting formulation might be 

 made out for homology. Are not the interactions between rela- 

 tively widely separated intellectual individuals, existing in the sea 

 of air surrounding the earth, in many ways actually homologous with 

 the passage of stimuli, etc., through more viscous fluid media between 

 cells? As, for instance, when two small organisms live in symbiosis; 

 or, where cells exist together as they do in blood; or, between cells 

 even more intimately organized. 



The concept of organisms of this higher or social grade suggests 

 the possibility of there being also low r er orders of organisms at the 

 other end of the accepted series. This idea is not new, for their 

 existence was specifically asserted by acute observers and adventurous 

 thinkers in the plainest of language at least half a century ago; but 

 at that time the supporting evidence was so meagre that the idea 

 did not rise to the dignity of an acceptable working hypothesis. 

 Now it is quite different. Today what we know about certain small 

 living elements, both inside and outside of cells, compels such a 

 working hypothesis/ if mayhap we are not already beyond the 

 hypothetical stage. 



Here again, size seems a prime determining element. When a 

 cell (really a relatively complex and large organism) transmits its 

 exceedingly numerous properties to its "descendants," nothing short 

 of an elaborate mobilization and census is adequate to the coming 

 transmigration. Hence follow mitosis and its complications. 



We are perhaps prone to forget that every cell has, in a great degree, 

 to care for itself; and so must have many of the multitudinous proper- 

 ties characteristic of the groups of cells constituting higher organisms. 

 It must nourish itself. "You can take the horse to food (or vice 

 versa), but you cannot make him eat; he must do that himself," 

 seems to summarize the situation. If the cell assimilates ("eats"), 

 and is to continue, then it must have mechanism adequate to select, 

 transport, digest, excrete, etc., and at least to take some part in 

 reproducing itself. All this complexity is because of the number of 

 its characteristics, and because of the size, i.e., the distances involved. 

 But what if all these be a hundredfold or more reduced, and the 

 system be at the same time "isolated" or individualized? Plainly, 

 the requirements would call for a simpler mechanism; cell-mechanism 

 would be so complicated as to be in the way. Under such conditions 

 simpler organisms, organisms simpler than cells, seem a logical 

 necessity. 



