146 



The Natuealist, 



are in reality plastic and variable. For instance, within the last year 

 or two Mr. Nicholson has shown us that no clear line of demarcation 

 can be draw^n between Fapaver Rhceas and Fapaver dubium, and Mr. 

 Arthur Bennett is fast reducing Fotamoyeton to the condition of Mix 

 and Hieraceum. Within the bounds of Britain we possess about two 

 hundred of w^hat Sir J. D. Hooker and Dr. Boswell call " sub-species " — 

 types of a kind that the majority of descriptive botanists place upon a 

 par with species, but which are not limited quite so definitely. In 

 addition to these 14U0 specific types, w^e acknowlege 3U0 or 400 

 named varieties — types betw^een which and their species no clear line 

 of demarcation can be drawn, but yet which are considered to be 

 thought worthy of a distinctive name. It would be a very inter- 

 esting subject for inquiry what this proportion that exists in our 

 flora, of six species of full rank to every one sub-species, and 

 every two varieties, implies. For my own part, if I were asked 

 to explain it, I could only say that I was completely unable to 

 do so. Although I do not think that any further work in this 

 direction is at all likely to modify the conclusion that has already 

 been indicated, there is a wide field here for collecting and correlating 

 facts, many of them of a kind that can be investigated suitably by a 

 local country botanist wdth limited leisure. For instance, it would be 

 quite within the scope of anyone with a small garden, to raise from 

 seed for a few years some of the numerous varieties of Viola tricolor, 

 and its sub-species arvends, lutea, and Curtisii, and keep a record of 

 what happened ; or to bring half-a-dozen of the native Epilobia or 

 Rumices into his garden, and make experiments in hybridizing them. 

 Work of this kind can be done far better in a quiet little garden in 

 the country than in a large establishment like Cambridge or Kew. 

 There is no one now that I know of who has any large number of 

 these " critical " British plants under cultivation, like Mr. Watson 

 used to have twenty years ago in his small garden at Thames Ditton. 



In accounting for the variation of our more variable specific types, 

 I do not think that the Darwinian principle of the propagation by 

 natural selection of characters that aid the organism in the struggle for 

 existence will carry us very far. In Eubas, for instance, in which of 

 all our indigenous generic types we get the widest range of variation 

 between remote extremes without any clear line of demarcation, one 

 can scarcely believe that any varietal or sub-specific type (a few 

 hybrids like R. pseudo-id oeus, and manifest degradations like R. Leesii, 

 excepted) possesses any character or capacity that, in the struggle for 

 life, will ^ive it an advantage over any other. The two facts in Bubus 



