132 J. HOPKTNSOK AJS^NIVEKSARY ADDRESS : 



What Man has been doing for the last few thousand years 

 Nature has been doing for untold ages. But there is this 

 difEerence. Nature selects only the best individuals, or those 

 which have some advantage in the struggle for existence, or 

 some special adaptability to changed circumstances. Man selects 

 those which have characters he wishes to perpetuate, not those 

 which give their possessors any advantage in their life -struggle, 

 in fact more often those which would place them at a disadvantage 

 if left to themselves and allowed to revert to their feral con- 

 dition ; and therefore, while a variety raised by Nature will 

 be preserved, or further modified in the same direction, a variety 

 raised by Man will tend to lose the characteristics which he has 

 endeavoured to impress upon it. This is called reversion to the 

 original type, and the fact of such reversion has by some been 

 thought to furnish one of the chief arguments against the theory 

 of Darwin. It rather furnishes an argument in favour of it, for 

 reversion of domestic animals and cultivated plants allowed to 

 run wild, to a type advantageous to them in their life-struggle, 

 is really an example of the beneficial effects of natural selection. 

 Moreover, characters acquired by domestication and cultivation 

 which are not disadvantageous are seldom entirely lost, although 

 it is evident that they are not so likely to be perpetuated as are 

 characters acquired under natural conditions. 



The struggle for existence amongst plants is chiefly against 

 competing plants of their own or other species, the winners in the 

 one case varying from the original type in some way by which 

 they obtain an advantage, and transmitting that variation to their 

 offspring, and in the other case driving out the competing species 

 by having greater vigour or more adaptability to any changing 

 circumstances. It is also a struggle against the depredations of 

 animals, the winners then being those which possess the best means 

 of defence, such as thorns or poisonous properties, or which are 

 the most inconspicuous. But flowers which are inconspicuous 

 vs^ill not attract insects, and therefore all such flowers depend, for 

 the continued existence of their species, upon seK-fertilisation. 

 All flowers which require to be cross-fertilised are conspicuous, 

 brightly coloured, or highly st-ented, so that insects may be at- 

 tracted to them. This is especially the case with orchids, in many 

 of which the adaptations for cross-fertilisation by the agency of 

 insects are exceedingly complex. Thus the development of floral 

 envelopes to the reproductive organs, and of the scent of flowers, 

 may be traced to the visits of insects, for whenever any variation 

 appears, if that variation increases the attraction of the flower to 



