BIONOMICS 265 



of such operations as budding, grafting, and striking cuttings 

 is quite different from that phenomenon whereby, say, a 

 crustacean can sometimes replace a missing limb. The latter 

 kind of regeneration, as Mr. Davidson points out, " does not 

 create a new individual, it merely provides a substitute 

 generally, if not invariably a poor one for some compara- 

 tively unimportant part which an existing individual has lost." 



Such regeneration seems to be only an effort of those 

 entities called the somatic cells, which in some instances 

 (owing to the particular contingencies of the life of the species) 

 have retained some of the powers of reproduction, which in 

 other cases, showing greater symbiotic and, therefore, more 

 reliant specialisation, have become totally deputed to the 

 sexual cells. 



Of the frequent regeneration of a plant from a bit of a 

 leaf, Spencer says : "It seems difficult to conceive that this can 

 be so ; but we see that it is so." Being mistaken about the true 

 inwardness of the phenomenon, he makes the following 

 remarks : 



Manifestly, too, if we are thus to interpret the reproduction of an 

 organism from one of its amorphous fragments, we must thus interpret 

 the reproduction of any minor portion of an organism by the remainder. 

 In the one case as in the other, the vitalized molecules composing the 

 tissues show their proclivity towards a particular arrangement; and 

 whether such proclivity is exhibited in reproducing the entire form, or 

 in completing it when rendered imperfect, matters not. For this 

 property there is no fit term. If we accept the word polarity as a 

 name for the force by which inorganic units are aggregated into a 

 form peculiar to them, we may apply this word to the analogous force 

 displayed by organic units. But, as above admitted, polarity, as 

 ascribed to atoms, is but a name for something of which we are ignorant 

 a name for a hypothetical property which as much needs explanation 

 as that which it is used to explain. 



I have already denned polarity as bio-dynamic character, 

 a definition which meets the case of " regeneration and 

 integrity" because of the implied incipient individuality. 



According to Spencer this specific polarity cannot dwell in 

 those proximate chemical components composing organic 

 bodies; not in the atoms of albumen, or fibrine, or gelatine. 



