Cockayne. — The Terms "Species" and " Variety" in Botany. 71 



morphological and artificial, the other physiological and natural. Thus, 

 according to the first conception, a species is a group of individuals which 

 are distinguished by certain definite and unchangeable characters, and 

 so differs from all other groups ; but according to the second conception a 

 species is a group of individuals resembling one another which on being 

 bred together produce like individuals. This second definition holds that a 

 species is a definite immutable entity, whereas the first is based, at best, 

 only on a superficial examination of numerous individuals, and so permits 

 the establishment of species which, as already explained, are not realities but 

 ideas, the limits of which may be extended or reduced according to the whim 

 of the taxonomist. Now, of recent years the careful experimental work of the 

 Mendelists and others has clearly shown that if the breeding-test be accepted 

 as the ultimate criterion of specific rank, species differing from one another 

 in the most minute, perhaps outwardly unrecognizable, characters would 

 have to be established by the thousand. That is to say, the main object of 

 a flora, which is the ready recognition of individual plants, would be nullified. 

 Therefore, since a true biological classification of individuals is probably 

 taxonomically impossible, taxonomy is forced in no few cases to adopt 

 such as is manifestly more or less artificial and to fall back upon the 

 procedure of the pre-evolutionary taxonomists. But, as already pointed 

 out, these investigators had no definite rules to observe, each was a law 

 unto himself, and the species of one were frequently of quite different value 

 from those of another, while it is even yet altogether a matter of opinion 

 which of the two would be the more correct. 



The classification of groups of individuals becomes far more complicated 

 when groups smaller than species are to be constructed. The Mendelist 

 gats over the difficulty by limiting his groups to the microspecies — i.e., 

 to the " biotypes," as he styles them, which breed true ; but such treatment 

 is not generally suitable for floristic botany. Still worse is the abandoning 

 of groups smaller than species, and, without any experimental test whatso- 

 ever, splitting up easily recognizable aggregate species into dozens of 

 so-called species which no one but their describer can possibly recognize ! 

 Even the orthodox taxonomist, when he attempts intensive work and 

 defines subspecies, varieties, subvarieties, and even forms, is not infre- 

 quently impossible to follow.* Leaving out of consideration the work of such 

 extremists, and turning to those who confine their groups of individuals 

 to " species " and " varieties," it is here that the greatest differences of 

 opinion occur, for the " species " of one are the " varieties " of another, 

 and so on. This does not matter greatly so far as concerns floristic botanists 

 themselves, but it is otherwise for investigators in other branches of botany, 

 who demand definite names for the plants they are dealing with, together 

 with some clue to their relationships. It is important, then, to get some 

 idea of what is meant by " variety," and in order to do so a brief consider- 

 ation of this term in taxonomy, from the time of Linnaeus, and incidentally 

 of " species " also, should be of service. 



Linnaeus himself considered varieties as anomalies to be brushed aside 

 as not worthy of the attention of the philosophical botanist. This curious 

 attitude has not even yet been altogether abandoned, for in few floras 



* A binomial, or even a trinomial, is a practical proposition, but if such names 

 as Bitter's (I.e. pp. 263—66) Acaena Sanguisorbae subsp. novae-zelandiae var. viridissima 

 subvar. rubescentistigma (not at all an extreme case) are to be used, then we had 

 much better go back to the pre-Linnean practice of a brief description of the group, 

 for it had the merit of telling something about the plantain question. 



