172 NATURAL SCIENCE [September 



What more do we want to prove that acquired characters are 

 hereditary ? I do not understand what he means when he says : — 

 " In every case these changes can be interpreted as . . . adapta- 

 tions or individual, non-hereditary modifications in the case of 

 plants." 1 That garden races are adaptations to their environment 

 is obvious, and to say that they cannot be hereditary is, as it seems 

 to me, to shut one's eyes gratuitously to the most conspicuous facts. 

 The " Student" Parsnip was "fixed" in five years, i.e., from 1847 

 to 1852, having been raised by Professor J. Buckman from seed 

 of the wild plant, and it is still pronounced to be " the best in the 

 trade " ; its acquired characters have been, therefore, relatively fixed 

 for half a century, though the plant's variability may never cease 

 to exist, because no so-called " fixed race " is absolutely stable. 

 Hence we constantly hear of Mr A's improved race of Mr B's pea, 

 bean, or what not. Nevertheless, that the typical garden form is 

 always reproduced, and that its sub-varieties or races come relatively 

 true by seed, is all that is wanted to establish the truth of acquired 

 characters being hereditary in plants. 



Migration, essential. — With regard to the origin and fixation 

 of varieties in nature a closer observation shows that, as a rule, 

 contrary to the Darwinian view, new varieties of plants have not 

 arisen among the parent types, but away from them. Thus, 

 Sir J. D. Hooker, who in his knowledge of the geographical distribu- 

 tion of plants is facile princcjjs, says : — " As a general rule the best 

 marked varieties occur on the confines of the geographical area which 

 a species inhabits." 2 Darwin also quotes A. de Candolle's opinion 

 that " plants which have very wide ranges generally present varieties ; 

 and this might have been expected (he writes), as they are exposed 

 to diverse physical conditions." 3 Precisely so ; but then this is 

 due to migration together with adaptation to the new physical 

 environments ; for the " diverse physical conditions " do not come 

 to the plants where the large populations have been supposed to 

 "row. It is interesting to see that both Darwin and Dr Wallace, 

 after asserting the importance of large populations ■ among which 

 new varieties are said to arise, are compelled by facts to admit 

 precisely the contrary. Thus, both Dr Wallace and Darwin observe 

 that the struggle for existence will be " most severe between in- 

 dividuals of the same species ; for they frequent the same districts, 

 require the same food, and are exposed to the same dangers." Such 

 is the condition said to be required for natural selection ; but now, 

 on the contrary, he tells us, " as an effect of this principle [?] we 

 seldom find closely allied species of animals or plants living together, 

 but often in distinct though adjacent districts where the conditions 



1 Loc. cit., p. 490. 2 " Introductory Essay to the Flora of Tasmania," p. v. 



:! "Origin, etc.," p. 43. 



