Chap. XIY. PREPOTENCY OF TEANSMISSION. 41 



The trtitli of the principle of prepotency comes ont more clearly 

 when distinct races are crossed. ' The improved Short-horns, not- 

 withstanding that the breed is comparatively modern, are generally 

 acknowledged to possess great power in impressing their likeness 

 on all other breeds ; and it is chiefly in consequence of this x)ower 

 that they are so highly valued for exportation.*^ Godine has given 

 a curions case of a ram of a goat-hke breed of sheep from the Cape 

 of Good Hope, which lorodnced oflspring hardly to be distingnislied 

 from himself, when crossed with ewes of twelve other breeds. But 

 two of these half-bred ewes, when put to a merino ram, x)roduced 

 lambs closely resembling the merino breed. Girou de Bnzareingnes '^ 

 found that of two races of French sheep the ewes of one, when 

 crossed during successive generations with merino rams, yielded 

 up their character far sooner than the ewes of the other race. 

 Sturm and Girou have given analogous cases with other breeds of 

 sheep and with cattle, the prepotency running in these cases 

 through the male side ; but I was assured on good authority in 

 South America, that when niata cattle are crossed with common 

 cattle, though the niata breed is prepotent whether males or females 

 are used, yet that the prepotency is strongest through the female 

 line. Tlie Manx cat is tailless and has long hind legs ; Dr. "Wilson 

 crossed a male Manx with common cats, and, out of twenty-three 

 kittens, seventeen were destitute of tails ; but when the female 

 Manx was crossed by common male cats all the kittens had tails, 

 though they were generally short and imperfect.^ 



In making reciprocal crosses between pouter and fantail pigeons, 

 the pouter-race seemed to be prepotent through both sexes over 

 the fantail. But this is probably due to weak power in the fantail 

 rather than to any unusually strong power in the pouter, for I have 

 observed that barbs also preponderate over fantails. This weak- 

 ness of transmission in the fantail, though the breed is an ancient 

 one, is said ^ to be general ; but I have observed one exception to 

 the rule, namely, in a cross between a fantail and laugher. The 

 most curious instance known to me of weak power in both sexes is 

 in the trumpeter pigeon. This breed has been well known for at 

 least 130 years: it breeds perfectly true, as I have been assured by 

 those who have long kept many birds : it is characterised by a 

 peculiar tuft of feathers over the beak, by a crest on the head, by 

 a singular coo quite unlike that of any other breed, and by much- 

 feathered feet. I have crossed both sexes with turbits of two sub- 

 breeds, with almond tumblers, si3ots, and runts, and reared many 

 mongrels and recrossed them ; and though the crest on the head 



* Quoted by Bronn, ' Gesi hichte p. 112. 



der Natur,' b. ii. s. 170. See Sturm, * ]\Ir. Orton, ' Physiology of Breed- 



' Lfeber Kacen,' 1825, s. 104-107. ing,' 1855, p. 9. 



For the niata cattle, see my ' Journal ^ Boitard and Corbie, 'Les Pigeons,* 



of Researches,' 1845, p. 146. 1824, p. 224. 



^ Lucas, ' L'Heredite Nat.,' torn. ii. 



