ANIMALS AND PLANTS 199 



reptiles (especially snakes), and, lastly, in many mammals such as 

 the bat, marmot, dormouse, etc. 



The last feature of analogy that I shall name is no less remarkable ; 

 it is this : just as there are simple animals constituting separate 

 individuals, and compound animals adhering together, communicating 

 at their base and sharing a common Ufe such as most of the polyps, 

 so also there are simple plants living as individuals and there are com- 

 pound plants where several live together, are grafted on to one another 

 and share a common life. 



The general rule among plants is to hve until they have produced 

 flowers and fruit or reproductive corpuscles. Their lives rarely last 

 for more than a year. Their sexual organs, if they have any, are only 

 of use for a single fertilisation ; so that when plants have reached 

 the goal of reproduction (seeds), they die and are completely 

 destroyed. 



In the case of a simple plant, death takes place after the production 

 of fruit ; and it is difficult, as we know, to propagate it otherwise than 

 by seeds or gemmae. 



Annual or biennial plants all appear to be in this position ; they 

 are simple plants ; and their roots, stems and branches are simply 

 vegetative products ; it is by no means every plant however that is 

 in this position, for the greater number of those that are known are 

 in reality compound plants. 



Thus, when I see a tree, shrub or perennial, it is not simple plants that 

 I have before me, but a multitude of plants hving together upon one 

 another and all sharing a common hfe. 



So true is this that if I were to graft the shoot of a cherry tree on 

 to the branch of a plum tree, and an apricot shoot on to another 

 branch of the same tree, these three species would Uve together and 

 share a common life while yet remaining distinct. 



The roots, trunk, and branches of such a plant consist purely of the 

 vegetable products of this common hfe, and of separate but adherent 

 plants which live upon it ; just as the general substance of a madrepore 

 is the animal product of numerous polyps which live together through 

 successive generations. But every bud in a plant is itself an individual 

 plant, which shares in the common life of all the rest, develops its flower 

 or inflorescence once a year, then produces fruit and may finally give 

 rise to a branch already supplied with other buds, that is, other in- 

 dividual plants. Each of these individual plants either fruits, in which 

 case it does so only once, or produces a branch which gives rise to 

 other similar plants. Any such composite plant is thus a vegetable 

 product, which continues to live after the destruction of all the in- 

 dividuals which have combined to produce it. 



