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living creature so that when present they are treated in cell-division 

 as constituents of the germs, we cannot conjecture. 



It was a commonplace of evolutionary theory that at least the 

 domestic animals have been developed from a few wild types. Their 

 origin was supposed to present no difficulty. The various races of 

 Fowl, for instance, all came from Gallus bankiva, the Indian Jungle- 

 Fowl. So we are taught ; but try to reconstruct the steps in their 

 evolution and you realise your hopeless ignorance. To be sure there 

 are breeds, such as Black-red Game and Brown Leghorns, which 

 have the colours of the Jungle-Fowl, though they differ in shape 

 and other respects. As we know so little as yet of the genetics 

 of shape, let us assume that those transitions could be got over. 

 Suppose, further, as is probable, that the absence of the maternal 

 instinct in the Leghorn is due to loss of one factor which the 

 Jungle-Fowl possesses. So far we are on fairly safe ground. But 

 how about White Leghorns ? Their origin may seem easy to 

 imagine, since white varieties have often arisen in well-authenticated 

 cases. But the white of White Leghorns is not, as white in nature 

 often is, due to the loss of the colour-elements, but to the action of 

 something which inhibits their expression. Whence did that some- 

 thing come? The same question may be asked respecting the heavy 

 breeds, such as Malays or Indian Game. Each of these is a 

 separate introduction from the East. To suppose that these, with 

 their peculiar combs and close feathering, could have been developed 

 from pre-existing European breeds is very difficult. On the other 

 hand, there is no wild species now living any more like them. We 

 may, of course, postulate that there was once such a species, now 

 lost. That is quite conceivable, though the suggestion is purely 

 speculative. I might thus go through the list of domesticated 

 animals and plants of ancient origin and again and again we should 

 be driven to this suggestion, that many of their distinctive characters 

 must have been derived from some wild original now lost. Indeed, 

 to this unsatisfying conclusion almost every careful writer on such 

 subjects is now reduced. If we turn to modern evidence the case 

 looks even worse. The new breeds of domestic animals made in 

 recent times are the carefully selected products of recombination of 

 pre-existing breeds. Most of the new varieties of cultivated plants 

 are the outcome of deliberate crossing. There is generally no doubt 

 in the matter. We have pretty full histories of these crosses in 

 Gladiolus, Orchids, Cineraria, Begonia, Calceolaria, Pelargonium, &c. 

 A very few certainly arise from a single origin. The Sweet Pea is 

 the clearest case, and there are others which I should name with 

 hesitation. The Cyclamen is one of them, but we know that efforts 

 to cross Cyclamens were made early in the cultural history of the 

 plant, and they may very well have been successful. Several plants 

 for which single origins are alleged, such as the Chinese Primrose, 

 the Dahlia, and Tobacco, came to us in an already domesticated 

 state, and their origins remain altogether mysterious. Formerly 

 single origins were generally presumed, but at the present time 

 numbers of the chief products of domestication, Dogs, Horses, Cattle, 



