2&2 EVOLUTION [Chap. IV 



Letter 203 I believe the principle in this case may be widely applied. I 

 like the figure, but I wish the artist had drawn a better sphinx. 

 With respect to beauty, your remarks on hideous objects and 

 on flowers not being made beautiful except when of practical 

 use to them, strike me as very good. On this one point of 

 beauty I can hardly think that the Duke was quite candid. 

 I have used in the concluding paragraph of my present book 

 precisely the same argument as you have, even bringing in 

 the bull-dog, 1 with respect to variations not having been 

 specially ordained. Your metaphor of the river 2 is new to 

 me, and admirable ; but your other metaphor, in which you 

 compare classification and complex machines, does not seem 

 to me quite appropriate, though I cannot point out what 

 seems deficient. The point which seems to me strong is that 

 all naturalists admit that there is a natural classification, and 

 it is this which descent explains. I wish you had insisted a 

 little more against the North British* on the reviewer assuming 



tion of Orchids, Ed. II., p. 163), is adapted to the visits of a moth with 

 a proboscis of corresponding length. He points out that there is no 

 difficulty in believing in the existence of such a moth as F. M filler has 

 described (Nature, 1873, p. 223) — a Brazilian sphinx-moth with a trunk of 

 10 to 11 inches in length. Moreover, Forbes has given evidence to show 

 that such an insect does exist in Madagascar (Nature, VIII., 1873, p. 121). 

 The case of Angrcecum was put forward by the Duke of Argyll as being 

 necessarily due to the personal contrivance of the Deity. Mr. Wallace 

 (p. 476) shows that both proboscis and nectary might be increased in 

 length by means of Natural Selection. It may be added that Hermann 

 Midler has shown good grounds for believing that mutual specialisation 

 of this kind is beneficial both to insect and plant. 



1 Variation of Animals and Plants, Ed. I., Vol. II., p. 431 : "Did 

 He cause the frame and mental qualities of the dog to vary in order that 

 a breed might be formed of indomitable ferocity, with jaws fitted to pin 

 down the bull for man's brutal sport ? " 



2 See Wallace, op. cit., pp. 477-8. He imagines an observer examining 

 a great river-system, and finding everywhere adaptations which reveal the 

 design of the Creator. " He would see special adaptation to the wants 

 of man in broad, quiet, navigable rivers, through fertile alluvial plains 

 that would support a large population, while the rocky streams and 

 mountain torrents were confined to those sterile regions suitable only for 

 a small population of shepherds and herdsmen." 



3 At p. 485 Mr. Wallace deals with Fleeming Jenkin's review in the 

 North British Review, 1867. The review strives to show that there are 

 strict limits to variation, since the most rigorous and long-continued 

 selection does not indefinitely increase such a quality as the fleetness 



