234 BREEDING. 
which have got good stock from all sorts of mares and bitches ; 
but in opposition to this may be instanced the numbers which’ 
have had enormous opportunities of showing their good qualities, 
but while they have succeeded with one or two, they have failed 
with the larger proportion of their harems. So with mares and 
bitches; some have produced, every year of their breeding lives, 
one or more splendid examples of their respective kinds, alto- 
gether independent of the horse.or dog which may be the parent, 
so long as he is of the proper strain likely to hit with hers. It is 
usually supposed that the sire impresses his external formation 
upon his stock, while the bitch’s nervous temperament is handed 
down ; and very probably there is some truth in the hypothesis. 
Yet it is clearer that not only do the sire and dam affect the pro- 
geny, but also the grandsires and granddams on both sides, and 
still further than this up to the sixth and perhaps even the seventh 
generations, but more especially on the dam’s side, through the 
granddam, great-granddam, &. There is a remarkable fact, con- 
nected with breeding which should be generally known, which is 
that there is a tendency in the produce to a separation between 
the different strains of which it is composed; so thata puppy com- 
posed in four equal proportions of breeds represented by a, B, C, and 
D, will not represent 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 particular 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 generally 
known, and then the evidence of the truth of these facts is patent 
to all. Among these dogs there was a well-known strain descended 
