GENERAL PRINCIPLES OF BREEDING. 173 



of which it is composed ; so that a puppy composed in four equal 

 proportions of breeds represented by a, b, c, and d, will not repre- 

 sent all in equal proportions, but will resemble one much more than 

 the others, and this is still more clear in relation to the next step 

 backwards, when there are eight progenitors : and the litter which, 

 for argument's sake, we will suppose to be eight in number, may 

 consist of animals each " going back " to one or other of the above 

 eight. This accounts for the fact that a smooth terrier bitch put 

 to a smooth terrier dog will often " throw " one or more rough 

 puppies, though the breed may be traced as purely smooth for 

 two or three generations, beyond which, however, there must have 

 been a cross of the rough dog. In the same way colour and par- 

 ticular marks will be changed or obliterated for one, two, or even 

 three generations, and will then reappear. In most breeds of the 

 dog this is not easily proved, because a record of the various 

 crosses is not kept with any great care ; but in the greyhound the 

 breed, with the colours, &c., for twenty generations, is often known, 

 and then the evidence of the truth of these facts is patent to all. 

 Amonor these doffS there is a well-known strain descended from a 

 greyhound with a peculiar nose, known as the " Parrot-nosed 

 bitch." About the year 1825 slie was put to a celebrated dog 

 called "Streamer," and bred a bitch called "Ruby," none of the 

 litter showing this peculiar nose ; nor did " Ruby " herself breed 

 any in her first two litters ; but in her third, by a dog called 

 " Blackbird," belonging to Mr. Hodgkinson, two puppies showed 

 the nose (" Blackbird " and " Starling "). In the same litter was 

 a most celebrated bitch, known as " Old Linnet," from which are 



