200 ZOOLOGICAL PHILOSOPHY 



By separating off parts of a plant, containing one or more buds or 

 including undeveloped elements, we can form at pleasure a number 

 of new living individuals similar to those from which they are taken, 

 without any necessity for taking the fruit. This in fact is just what 

 horticulturists do when they take slips, layers, etc. 



Now just as nature has made compound plants, so too she has made 

 compound animals ; and for this purpose she has made no change in 

 the nature of either animals or plants. It is quite as absurd to call 

 compound animals by the name of plant-animals, as it would be to 

 caU compound plants by the name of animal-plants.^ 



If the name of zoophyte were given a century ago to compound 

 animals of the class of polyps, the error was excusable ; the low state 

 of knowledge then existing about animal nature made this term 

 less obnoxious ; but now things have altered, and it cannot be a 

 matter of indifference that a class of animals should receive a name 

 which embodies a false notion of the objects indicated. 



Let us now enquire what life is, and what are the conditions for its 

 existence in a body. 



' When we confine our attention to the substances produced by vegetation or 

 by animals, we often find cases where it is difficult to decide whether they belong to- 

 the plant or animal kingdom ; chemical analysis of these bodies sometimes decides 

 in favour of animal substances when their shape and organisation are suggestive of 

 true plants. Several genera referred to the family of algae provide examples of 

 this difficulty : it would thus seem to follow that there is an almost imperceptible 

 transition from plants to animals. 



I do not think so : on the contrary, I am thoroughly convinced that it it were 

 possible to examine the actual animals which form the membranous or filamentous 

 polyparies so closely resembling plants, the uncertainty as to their true nature would 

 at once be removed. 



