58 LUTHER BURBANK 



of protective envelope separating the individual 

 from the rest of the cosmos, so that it can enjoy 

 individual life and in no other way could this 

 permanently be secured. Even chemicals do not 

 retain their individual character unless inclosed 

 in packages or bottles or cells of some kind, 

 so the cell is a unit of all individual life and it is 

 very evidently necessarily so, in order to meet 

 the obstacles to full development under oppos- 

 ing environment, but it is plain that environ- 

 mental obstacles can be more readily overcome 

 by a combination of cells. Of course these cell 

 colonies would, in the very nature of the circum- 

 stances, be better adapted to survive than single 

 individuals; thus colonies must very naturally 

 have arisen by accretion, producing, during the 

 lapse of ages, all the various forms of vegetable 

 and animal life which the conditions on our 

 planet have now brought and are yet bringing 

 forth. Cell colonies must preserve their very 

 existence by adapting themselves to the aid of 

 all other members of the cell colony — therefore 

 must become specialists in certain directions; 

 thus seed, bark, wood, and leaf cells in plants; 

 and blood, liver, brain, bone, and muscle cells 

 in animal life, though retaining their individu- 

 ality as modified cells, yet have become, by stress 

 of environment, specialists, for by specialization 



