OF LIVING MATTER 25 



constitute a living whole, for the one animal may be divided 

 into two, and the two into four or more, and each part will grow 

 into an organism like that of which it is a segment — the parts grow 

 into wholes, and in the place of the one individual organism we get 

 four or more others similar in kind. 



These also are the kinds of phenomena and modes of life 

 with which we are familiar throughout the vegetable kingdom — 

 nowhere do we meet with anything like that same amount of 

 integration or individuation which is characteristic of the higher 

 animals. Mere fragments of plants in the form of buds, ' cuttings,' 

 or portions of the root, separated from the parent organism, are 

 as we know capable of reproducing plants similar to those from 

 which they have been derived. The ' tendency to individuation ' 

 exists here also, but even in the most perfect plant the accom- 

 plished result is small indeed, when compared with what we 

 encounter among animals. The absence of a nervous system, 

 however, combined with the less perfect condition of the vascular 

 system, are sufficient to account for this want of integration in 

 the plant, and the great amount of independence shown by its 

 individual parts. 



Such are some of the principal differences in the nature of the 

 'life,' or aggregate vital manifestations of the members of the 

 animal and of the vegetable kingdoms : and great as are the 

 differences between the phenomena of the higher and of the lower 

 forms of these, we may look for even still lower manifestations 

 of life in a group of organisms whose characteristics, whether 

 structural or functional, are often so little marked as to make 

 the most philosophic naturalists unable to assign them a definite 

 place in either the one or the other of these organic kingdoms. 



It might have been expected, in accordance with the doctrines 

 of Evolution, that the lowest living things would present characters 

 of the most general description. They ought to be simply living 

 things, without visible organisation, and should as yet present 

 no special characters by virtue of which a place might be assigned 

 to them either in the vegetable or in the animal kingdom. The 

 older naturalists thought that every living thing must be either 

 an animal or a plant, and they accordingly ranged all organic 

 forms under one or other of these categories. But there were 

 certain of them whose characteristics were so indefinite that they 

 could really claim for themselves, as we have said, no unquestioned 



