GENERAL INTRODUCTION. lix 



frequently, if not invariably, resemble the ordinary 

 turtle-dove. Wlien, however, a male white Java dove 

 is crossed with an ordinary turtle-dove hen, a white bird 

 is occasionally obtained. Intermediate forms never 

 seem to occur ; at the most the faintest yellow tino-e is 

 at times visible, chiefly at the tips of the wings. The 

 cross-bred birds are very fertile inter se, and when the 

 offspring of a white Java cock they yield about an equal 

 number of white and turtle-coloured birds. Even when 

 a cross-bred dark bird was mated with a pure-bred white 

 Java bird the result was an ordinary turtle-dove, — not, as 

 might have been expected, a white bird. With the 

 turtle-doves as with the rabbits, the older type is pre- 

 potent. Experiments with closely inbred white birds 

 might give somewhat different results."^ 



As already mentioned, a duck, the offsprino- of a 

 black Cayuga drake and a common wild duck, produced 

 to a wild drake seventeen young. Of these, seven take 

 after the wild sire, the others after the black Cayuga 

 grandsire. In this case the influence of the wild sire is 

 not as marked as might have been expected. With the 

 help of reversion they might very well all have assumed 

 the dress of the common wild duck. 



Hybrids between the wild pheasant and various breeds 

 of fowls are common. Several I have examined were 

 more like fowls than pheasants ; on the other hand, a 

 cross between a bantam cock and a grouse is described 

 by Millais as generally more resembling a grouse than a 

 bantam. 



Of the nine zebra-horse hybrids I have bred, only two 

 in their make and disposition take decidedly after the 

 wild parent. As fully explained below, all the hybrids 

 differ profoundly in the plan of their markings from the 

 zebra, while in their ground colour they take after their 

 respective dams or the ancestors of their dams far more 

 than after the zebra, — the hybrid out of the yellow and 



* The experiments with turtle-doves were made by Mrs. Cospatrick 

 Dunbar, partly in London and partly at Earnbank, Bridge of Earn, 

 Perthshire. 



