THE DARWINIAN THEORY. 



85 



be found. The fact also that occasionally a young pigeon 

 (e. g. a tumbler) is produced with the white croup, double black 

 wing-bar, and barred and white-edged tail-feathers — in short, in 

 the very livery of the original Eock-Pigeon — is a very strong 

 corroboration of its direct descent therefrom. No one will for a 

 moment suppose, however, that these various breeds of pigeons 

 have been solely produced by the modifying circumstances of 

 habit and external conditions ; on the contrary, it is at once 

 perceived that they have been effected by the adaptation of man, 

 who has sometimes had less a view to the creature's benefit than 

 his own caprice. 



It seems bold to emphasize this modification by man, yet 

 some may be acquainted with facts that prove the occurrence of 

 wonderful changes in this respect in a single race of cattle or 

 sheep, even during a man's lifetime. The same is observed in 

 the domestic fowls — which some suppose to have sprung from a 

 single species — in horses, and in garden flowers and fruits. It is 

 known that the cabbage, cauliflower, broccoli, kale, and kohlrabi 

 are derivatives of one species, and rape or colza, turnip and 

 probably ruta-baga (Swedish turnip) of another species. The late 

 Hugh Miller, who was well known to have very strong anti- 

 pathies to the development-theory (Darwin's in the present day), 

 observes : — " Man is a mighty improver of creation. He adds 

 to the beauty of the flowers which he takes under his charge, to 

 the delicacy and fertility of the fruits ; the seeds of the wild 

 grasses become corn beneath his care ; the green herbs grow 

 great of root and bulb, or bulky and succulent of top and leaf ; 

 the wild produce of nature sports under his hand ; the rose and 

 the lily broaden their discs and multiply their petals ; the harsh 

 green crab swells out into a delicious golden-rhinded apple 

 streaked with crimson." And so the udders of the cow and 

 goat enlarge, the fleece of the sheep alters, and the cocoon 

 of the silkworm becomes more bulky. The key to all this, says 

 Darwin, is man's power of accumulative selection ; Nature gives 

 successive variations ; man adds them up in certain directions 

 useful to him or that satisfy his caprice. 



In antagonism to the foregoing remarks, one of the most 

 formidable of Darwin's opponents, the celebrated Prof. Louis 

 Agassiz, of the United States, affirmed that Darwin had failed to 



