n. UNCERTAINTY OF SPECIES. 39 



by another botanist, Mr. Andrews. And yet tbis is prac- 

 tically the reasoning of botanists who thus " raise varie- 

 ties to the rank of species." Because one or few speci- 

 mens are found to differ from the rest in two very trivial 

 peculiarities of form, — therefore they have also all the 

 permanent and physiological peculiarities which are be- 

 lieved to divide species. Surely, this cannot be regarded 

 as logic of the highest quality ! 



It is not here insinuated that the practice of thus 

 guessing species on very imperfect grounds, rather than 

 seeking to know them by experimental observation, is 

 anywise peculiar to the learned Author of the Manual of 

 British Botany. On the contrary, he acts in this wise 

 only after the fashion of most other technical descri- 

 bers. His Manual is resorted to because it affords very 

 recent examples, specially apiDcrtaining to the flora of 

 Britain ; and which are thus more apposite illustra- 

 tions than any of the quasi-species proposed in other 

 countries, or at older dates in this country. It can 

 readily be shown that the practice of inventing or 

 adopting book species, which may or may not be recog- 

 nized eventually as natural species, is no new practice 

 with British writers. The uncertainty and variability in 

 the numbers of species, at different dates and in different 

 books, may be cited in evidence that book species and 

 natural species are not at all identical,, assuming the 

 latter to have a real or proved existence. 



Perhaps the tabular and numerical form may best 

 serve to illustrate the wide diversities of view as to spe- 

 cies, prevalent among the botanists who have published 

 Floras of the British Islands within the last half-century 

 or a little more. The number of species into which the 

 several Authors have divided some of the larger genera, 

 is indicated opposite their names in the subjoined list; 



