6 THE LANGUAGE OF BOTANISTS. 



is capable of living when separated from the rest and of producing a new inde- 

 pendent plant, the parts of a shoot came to be considered as being individuals, and 

 the term " Anajjhytes " was applied to them. We shall see hereafter the extent to 

 which this conception is of importance in relation to the subject of alternation of 

 generations. It would be out of place to treat it more fully at present. 



Another conception of the plant-individual must also be mentioned here. 

 When the impossibility of defining it as indivisible was recognized, the strange 

 expedient was invented of assuming the existence of divisible individuals and of 

 representing all parts which have been produced asexually and have become inde- 

 pendent as belonging to a single individual. A potato puts forth thirty or forty 

 fresh tubers in the course of a few years, and all these were considered as collectively 

 constituting one single individual, as also were the countless young carnation- 

 plants which are to be dei'ived by means of cuttings from one old plant. The 

 general rule was that only an organism produced by sexual process was to pass as 

 an individual. Cuttings, tubers, and the like, detached from such an organism 

 would be, according to this conception, merely parts of one individual, even though 

 they were capable of living quite independently and at a distance from one another. 



This definition, the invention of philosophers, has never been taken seriously 

 by naturalists, and I only cite it because it introduces another important problem 

 which I purpose to ti'eat in an exhaustive manner in the first three sections of 

 this volume, namely, the question of the propagation or generation of plants. The 

 modes of reproduction in plants have been subjected in recent times to most patient 

 investigation on the part of botanists gifted with the keenest powers of observation, 

 and their researches have led to the conclusion that in most — probably in all — 

 divisions of the vegetable kingdom two kinds of propagation occur. In each case 

 a single protoplast forms the starting-point for the new individual; but, in the one, 

 this protoplast does not require the special stimulus afforded by union with another 

 protoplast, whereas, in the other, in order that a new individual organism may be 

 produced, a pairing — i.e. a union of the substances — of two protoplasts, which have 

 come into being at different spots, must take place. The former is called asexual 

 reproduction, the latter sexual reproduction. All reproductive bodies ai-ising 

 asexually are included under the name of brood-bodies, whilst those which are 

 associated with the sexual process may be termed broadly fruits. 



There are all grades of brood-bodies, from the single cell to the completely 

 formed plant. Brood-bodies, if unicellular, are termed spores, if multicellular, 

 thallidia; and those which constitute rudimentary shoots are called buds. The 

 bud form of brood-body either detaches itself from the living parent-plant, or else, 

 as more frequently happens, it becomes independent through the death of the plant 

 from which it sprang. In the latter case the off-shoots remain in the immediate 

 vicinity of the parent-plant. In the case of trees and shrubs the buds do not sever 

 themselves fi'om the axis on which they were developed, but continue their connec- 

 tion with it as they grow into shoots, and in this manner are formed those 

 compound individuals to which reference has been already made. It is much less 



