44 INHERITANCE. Chap. XIV. 



for hybrids raised, from five differently coloured liens differed 

 greatly in plumage. I formerly examined some curious hybrids in 

 the Zoological Gardens, between the Penguin variety of the com- 

 mon duck and the Egyptian goose (Amer cegyptiacus) ; aud al- 

 though I will not assert that the domesticated variety prepon- 

 derated over the natural species, yet it had strongly impressed its 

 unnatural upright figure on these hybrids. 



I am aware that such cases as the foregoing have been ascribed 

 by various authors, not to one species, race, or individual being 

 prepotent over the other in impressing its character on its crossed 

 offspring, but to such rules as that the father influences the ex- 

 ternal characters and the mother the internal or vital organs. But 

 the great diversity of the rules given by various authors almost 

 proves their falseness. Dr. Prosper Lucas has fully discussed this 

 point, and has shown ls that none of the rules (and I could add 

 others to those quoted by him) apply to all auimals. Similar rules 

 have been announced for plants, and have been proved by Gartner 19 

 to be all erroneous. If we confine our view to the domesticated 

 races of a single species, or perhaps even to the species of the same 

 genus, some such rules may hold good ; for instance, it seems that 

 in reciprocally crossing various breeds of fowls the male generally 

 gives colour ; 20 but conspicuous exceptions have passed under my 

 own eyes. It seems that the ram usually gives its peculiar horns 

 and fleece to its crossed offspring, and the bull the presence or 

 absence of horns. 



In the following chapter on Crossing I shall have occasion to 

 show that certain characters are rarely or never blended by cross- 

 ing, but are transmitted in an unmodified state from either parent- 

 form ; I refer to this fact here because it is sometimes accompanied 

 on the one side by prepotency, which thus acquires the false 

 appearance of unusual strength. In the same chapter I shall 

 show that the rate at which a species or breed absorbs and ob- 

 literates another by repeated crosses, depends in chief part on 

 prepotency in transmission. 



In conclusion, some of the cases above given, — for instance, 

 that of the trumpeter pigeon, — prove that there is a wide 

 difference between mere inheritance and prepotency. This 

 latter power seems to us, in our ignorance, to act in most cases 

 quite capriciously. The very same character, even though 

 it be an abnormal or monstrous one, such as silky feathers, 

 may be transmitted by different species, when crossed, either 

 with prepotent force or singular feebleness. It is obvious, 



18 'L'Hered. Nat.,' torn. ii. book ii. Museum,' torn. i. p. 148) has arrived 

 ch. i. at a similar conclusion. 



19 ' Bastarderzeugung,' s. 264-2GG. 20 'Cottage Gardener,' 1856, pp 

 Naudin (' Nouvelles Archives du 101, 137. 



