DARWIN AS ECOLOGIST. 



29 



"Essay on Population"): — "Propagation [descent] explains why 

 modem animals, same type as extinct; whiQh is law; almost proved." 

 "Countries longest separated, greatest differences; if separated from 

 immersage, possibly two distinct types, but each having its represen- 

 tatives — as in Australia." "Will this apply to the whole organic 

 kingdom, when our planet first cooled? " 



Here we have the first glimpse of the idea of evolution, with the 

 differentiation of species by isolation in different regions. In the 

 following sentence we find Darwin appealing to Adaptation, i.e., the 

 first observation of ecology. "Why does individual die? To per- 

 petuate certain peculiarities (therefore adaptation) and obliterate acci- 

 dental varieties and to accommodate itself to change (for, of course, 

 change, even in varieties, is accommodation). Now this argument 

 applies to species."* 



In this instructive passage we find a hint of natural selection in the 

 words "obliterate accidental varieties," corresponding to "injurious 

 variations which would be rigidly destroyed "f ; while accommodating 

 itself to change is self -adaptation. In other words, exactly the same 

 inferences are the outcome of modern ecology. 



Again, referring to a variety of an ostrich and a Galapagos bird, he 

 says: — "This requires [the] principle that the permanent variations 

 produced by . . . changing circumstances are continued and produced 

 according to the adaptation of such circumstances, and therefore that 

 death of species is a consequence ... of non-adaptation [this is called 

 'injurious'] in the 'Origin &c.' to [changed?] circumstances."! 

 This was written before 1842. 



Dr. F. Darwin quotes an interesting remark of Huxley's, which 

 corroborates what I am contending. He said: — " Much more weight 

 is attached to the influence of external conditions in producing 

 variation and to the inheritance of acquired habits than in the 

 * Origin &c.' "§ 



If we now pass from these early views to his more precise expres- 

 sion in later years, we find him writing as follows: — " If we reflect 

 on the vast diversity of the plants and animals which have been 

 cultivated ... we are driven to conclude that this great amount of 

 variation is due to the conditions of life not being so uniform and 

 somewhat [extremely?] different from those to which the parent- 

 species had been exposed under nature." 



" The conditions of life appear to act in two ways, (1) directly on 

 the whole organization or on certain parts; and (2) indirectly by affect- 

 ing the reproductive system. "|| 



" With respect to Direct Action, the effects on the offsprings are 

 either Definite or Indefinite. 



" They may be considered as definite, when all or nearly all the 



* Life, etc., ii. pp. 5, 7. t Oriqin, sixth edition, p. 63, 



X TAfe, dbc, ii. p. 8. § Ibid.,^ p. 14. 



II Origin, cfcc, sixth edition, p. 5. The italics are mine. 



