296 
On Cross Breeding. 
We are, however, of opinion that, in the majority of instances, the 
height in the human subject, and the size and coiiiour in animals, 
is influenced inuck more by the male than the female parent ; and, 
on the other hand, that the constitution, the chest, and vital 
organs, and the forehand generally, more frequently follow the 
female. 
We have dwelt on this point the more because on it hinges the 
difficulty of eflfecting certain improvements in breeding by means 
of crossing, and the still greater difficulty of establishing a new 
breed by such means. So great is this difficulty that many 
breeders, finding their attempts at such improvements so frequently 
baffled, or observing this to be the case in the practice of others, 
cling with superstitious tenacity to the doctrine of purity of 
blood, believing it to be the Ark in which alone true safety is to 
be found. 
Now pure breeding, which, when carried to an excess, is called 
in-and-in breeding, has its advantages as well as its disadvantages. 
Its friends observe with great force, that when we have in breed- 
ing reached great excellence, it is folly to risk the loss of such 
excellence by means of crossing ; and the more so as the defects 
of a parent may disappear in a first or second, and reappear 
in the third or fourth generation ; " breeding back," as it is 
commonly termed. A friend of the writer's, Mr. John Clark, of 
Lockerly, a strenuous advocate of pure breeding, observes that a 
correspondent in Suffolk informs him, that he had seen the cross 
tried between the old Norfolk and Down sheep, and the first cross 
was admirable, but they soon became disproportioned and un- 
sightly ; also the Down and Leicester in some midland counties 
figured for a time, and then for the same reasons were given 
up, and such he thinks will be the fate of the New Oxfords, or 
the mixture of the Cotswold and the Down. He adds, that for 
the last four years he has used rams from the cross with Down 
ewes, and the offspring have answered his purpose forfaiting 
lambs, but one lamb in ten presents unmistakeable evidence of 
its mongrel origin. 
Again, it is urged that great excellencies can only be 
perpetuated by union with similar excellencies, and beyond 
all this that there is a certain amount of advantage from an 
unstained lineage — from the very possession of breed, as it is 
designated. The objectors to in-and-in breeding urge, that by so 
doing we engender weakness of constitution, diminution of size, 
hereditary diseases, and also a tendency to barrenness ; but it is 
argued in reply to sucli objections, that they occur from want of 
sufficient care in weeding out defective animals, whether as 
respects constitution or size. It is a well-established fact, that in 
