1 882.] Organic Physics. 559 



is no reason to conclude that it does not occur, and it is by no 

 means improbable that their nutrient process consists, partly at 

 least, in an assimilation of the molecules, or the budded gem- 

 mules, of other leucocytes. 



With these preliminaries we may proceed to consider the 

 hypothesis that the leucocytes are the true germinal particles, 

 which embrace in their organization the chemical and physical 

 characteristics of every region of the body, this generalism of 

 constitution being produced by successive combinations of the 

 leucocytes, until they finally produce composite germs which are 

 true generalized copies of the whole body. 



From this point of view the hypothesis which looks upon the 

 animal body as a colony of individual cells may not be an untrue 

 one. Each cell depends for its individual life upon the nutrient 

 pabulum elaborated for it by the combined labor of all the other 

 cells of the body. It does not go forth as an individual in search 

 of food, for its proper food is brought to it. But though fixed in 

 position, its individual life resembles that of the Protozoan. It 

 assimilates food, grows, and divides into new cells. And it is 

 quite possible that all these cells do not remain united. Some of 

 them may be thrown off into the lymphatic fluid which bathes the 

 mother-cell/ Each cell may thus, in addition to its coherent off- 

 spring, send off independent offspring, to wander out into the 

 world at large of the nutrient fluid. 



Thus from every cell of the body may come wandering off- 

 spring, each a perfect copy of the mother-cell. The inducement 

 to their being thrown off may be the better chances for nutrition 

 offered by a free existence in the nutrient fluid. It is one phase 

 of the struggle for existence and adaptation to circumstances, 

 Which displays itself everywhere in nature, from its lowest to its 

 Highest conditions. Possibly each cellular unit of the body per- 

 forms a double duty. It acts both as a constituent part of the 

 body and as a free individual. In its former office some of its 

 daughter-cells remain coherent, and aid in the growth of the tis- 

 sues - In its latter office some of its daughter-cells are budded 

 off into the surrounding fluid to pursue an^individual life of their 

 ou 'n- In this respect it reproduces the Protozoan mode of life, in 

 which all new cells are budded off into the surrounding fluid as 

 ^parate individuals. 



Such a process is not improbable in itself. We can with some 



