THE PRESENT POSITION OF CELL-THEORY. 105 



seizes on the molecules of a crystal and takes them in 

 between its own molecules ; in the former case the dry 

 organic body seizes on the molecules of water and forces 

 them between its own. These reasons are held by von 

 Sachs and Nageli to be among the weightiest for regarding 

 protoplasm as an "organised" body, in the sense of being 

 made up of micellae, and not as being a structureless slime 

 or fluid. 



No doubt they are weighty reasons for regarding or- 

 ganic substances such as gelatine, starch grains, cell walls, 

 etc., as being composed of combinations of polyatomic 

 molecules into groups of a higher order, and there is no 

 objection to giving these groups a name, such as micellae. 

 But the admission that such groups exist does not really 

 bring us much nearer to an explanation of the phenomena 

 of life. Von Sachs himself points out that even in the 

 region of pure chemistry it is necessary to assume that 

 polyatomic molecules are grouped into closer molecular 

 unions, thus giving rise to chemical properties which did 

 not belong to the individual molecules. 



Gelatine, starch grains and cellulose are not living but 

 dead substances, and the fact that the behaviour of dead 

 organic substance finds an explanation on a theory of 

 micellar structure is but a very small step towards the 

 explanation of the very different behaviour of living sub- 

 stance. The micellae may exist in the organic substances 

 in question, but they are not to be confounded with biophors ; 

 the very fact that the properties of dead substances may be 

 attributed to their existence shows that they cannot be con- 

 sidered as bearers of vital properties. 



In point of fact the living substance, which we generalise 

 under the name of protoplasm, behaves quite differently 

 in respect of the imbibition of water to the dead substances 

 which are derived from it. An amoeba or an infusorian, 

 living in the water, does not imbibe it as a mass of gelatine 

 would. But when it dies in the same water it immediately 

 begins to swell up, and eventually bursts and disintegrates. 

 So that we see that with respect to this very property which 

 is held to be a reason for assuming a micellar structure of 



