70 ON CERTAIN CHARACTERS Chap. XV 



some characters refuse to blend, and are transmitted in an un- 

 modified state either from both parents or from one. When grey 

 and white mice are paired, the young are piebald, or pure white or 

 grey, but not of an intermediate tint; so it is when white and 

 common collared turtle-doves are paired. In breeding Game fowls, 

 a great authority, Mr. J. Douglas, remarks, " I may here state a 

 " strange fact : if you cross a black with a white game, you get 

 " birds of both breeds of the clearest colour." Sir E. Heron crossed 

 during many years white, black, brown, and fawn-coloured Angora 

 rabbits, and never once got these colours mingled in the same 

 animal, but often all four colours in the same litter. 18 From cases like 

 these, in which the colours of the two parents are transmitted quite 

 separately to the offspring, we have all sorts of gradations, leading 

 to complete fusion. I will give an instance : a gentleman with a 

 fair complexion, light hair but dark eyes, married a lady with dark 

 hair and complexion : their three children have very light hair, but 

 on careful search about a dozen black hairs were found scattered in 

 the midst of the light hair on the heads of all three. 



When turnspit dogs and ancon sheep, both of which have dwarfed 

 limbs, are crossed with common breeds, the offspring are not inter- 

 mediate in structure, but take after either parent. When tailless or 

 hornless animals are crossed with perfect animals, it frequently, but 

 by no means invariably, happens that the offspring are either 

 furnished with these organs in a perfect state, or are quite destitute 

 of them. According to Eengger, the hairless condition of the 

 Paraguay dog is either perfectly or not at all transmitted to its 

 mongrel offspring ; but I have seen one partial exception in a dog 

 of this parentage which had part of its skin hairy, and part naked, 

 the parts being distinctly separated as in a piebald animal. When 

 Dorking fowls with five toes are crossed with other breeds, the 

 chickens often have five toes on one foot and four on the other. 

 Some crossed pigs raised by Sir E. Heron between the solid-hoofed 

 and common pig had not all four feet in an intermediate condition, 

 but two feet were furnished with properly divided, and two with 

 united hoofs. 



Analogous facts have been observed with plants : Major Trevor 



13 Extract of a letter from Sir R. less condition of crossed South Ameri- 



Heron, 1838, given me by Mr. Yarrell. can dogs, see Rengger, ' Saugethiere 



With respect to mice, see ' Annal. des von Paraguay,' s. 152 : but 1 saw in 



Sc. Nat.,' torn. i. p. 180; and I have the Zoological Gardens mongrels, 



heard of other similar cases. For from a similar cross, which were 



turtle-doves, Boitard and Corbie, ' Les hairless, quite hairy, or hairy in 



Pigeons,' &c, p. 238. For the Game patches, that is, piebald with hair, 



fowl, 'The Poultry Book,' 1866, p. For crosses of Dorking and other 



128. For crosses of tailless fowls, fowls, see ' Poultry Chronicle,' vol. ii. 



see Bechstein, 'Naturges. Deutsch.' p. 355. About the crossed pigs, ex- 



b. iii. s. 403. Bronn, ' Geschichte tract of letter from Sir R. Heron to 



der Natur,' b. ii. s. 170, gives analo- Mr. Varrell. For other cases, see P 



gous facts with norses. On the hair- Lucas, ' L'Hertkl. Nat.' torn. i. p. 212 



