332 



Diseases of Sheep. 



It is also within the experience of every farmer in large breed- 

 ing counties, that, in certain cases where a remarkably good 

 stock has been acquired, the breeder is even jealous of the intro- 

 duction of a stranger into his flock, and proceeds on the in-and-in 

 system for many years, Vv^ith no perceptible falling off, and in- 

 deed generally with obvious improvement in his breed. 



Lord Somerville, whose name is high as an agricultural writer, 

 was decidedly opposed to crossing dissimilar breeds ; and Dickson, 

 in his ^ Practical Agriculture,' ranges himself on the same side. 

 On the other hand, it has fallen within the observation of every per- 

 son, that, even in the human race, frequent intermarriages in the 

 same family, in successive generations, have a tendency to reduce 

 the offspring in vigour and size, and to perpetuate constitutional 

 affections. So^ again, to return to the animal creation, it is per- 

 fectly understood that the race-horse degenerates in speed, and 

 especially in strength, if too much of the same family is allowed 

 to remain in the stock : while there is scarcely any sportsman, 

 who has been in the habit of breeding his own dogs, that has not 

 perceived a gradual but certain diminution of size and power in 

 such as are bred on the in-and-in principle. I have been in- 

 formed by a friend, who for many years has had in his kennel a 

 particular and valuable pointer breed, that he has uniformly 

 found all the puppies weak and diminutive after the third degree 

 in lineal descent, if bred without a cross ; though the properties 

 of scent and docility seem in no measure lost. The truth would 

 seem to lie between the extremes. It is well known that in all 

 animals like begets like, and that this principle is so general that 

 faults and defects, as well as strength, size, and other qualities, 

 descend hereditarily. So long as the inherited qualities are on 

 the favourable side, it would seem impolitic to cross the blood ; 

 but, if, in the course of time, any peculiar deficiency of form in 

 the proportion or symmetry of the animal becomes conspicuous. 



ascertain the extent of deviation from strict in-and-in breeding requisite to 

 check its ill e&ecXs.— January 25th, 1840. Richard Owen. 



In communicating this note, kindly transmitted at my request by 

 Richard Owen, Esq., F.R. S., Hunterian Professor of Comparative Ana- 

 tomy to the Royal College of Surgeons, and Vice-Ch airman of the Zoo- 

 logical Society, I may remark, that whenever, in my South Down flocks, 

 breeding in-and-in has been tried, I have found the produce deficient in size 

 and constitution. In my park at Goodwood, the fallow-deer are smaller than 

 formerly ; I believe, because no fresh blood has been introduced. In the 

 Highlands of Scotland, it is well known that the Red Deer Stags often, at 

 tile rutting season, travel many miles to other forests, where they remain 

 for a certain time, and then return to the district from which they came. 

 In-and-in breeding is, therefore, to a certain extent avoided, and the deer 

 have not, as fiir as I can learn, degenerated. — Richmond. 



