22 CELL THEORY BEFORE 1860. 



expression reciprocal action, being taken in its widest 

 sense as implying the preparation of material by one 

 elementary part, which another requires for its own 

 nutrition. Thus the majority of the individual cells 

 may be unable to subsist when separated from the 

 whole organism, because it is only while together 

 they can obtain the nutriment and other conditions 

 requisite for continued life. Therefore, " the cause of 

 nutrition and growth resides, not in the organism 

 as a whole., but in the separate elementary parts 

 the cells. The failure of growth in the case of any 

 particular cell, when separated from an organized body, 

 is as slight an objection to this theory, as it is an 

 objection against the independent vitality of a bee, 

 that it cannot continue long in existence after being 

 separated from its swarm. The manifestation of the 

 power which resides in the cell depends upon con- 

 ditions to which it is subject only when in connection 

 with the whole (organism) " (Syd. Soc., 1847, p. 192). 



Nevertheless when we see that in the cell theory 

 proper, the smallest living unit is a compound possess- 

 ing structure, viz., the wall and contents which are 

 differently constituted both physically and chemically, 

 we can no longer conceive that its vitality can be the 

 property of the matter of which it is composed. For 

 a property must be present in full measure and in- 

 separable from the smallest indivisible molecule of 

 which any mass is composed. For instance, no one 

 would think of attributing aquosity or the distinguish- 

 ing properties of water to it only in the form of single 

 liquid drops or single crystals of ice, far less to a drop 

 surrounded by a coating of something else, but always 



