IN-BREEDING. 41 



betwreen the nearest blood relations. It applies to individuals of the same Sub- 

 variety but of distinct families, to varieties or races, to sub-species, as well as 

 to quite distinct species. 



In this latter case, however, whilst size, vigor, precocity and hardiness are, 

 with rare exceptions, gained, fertility, in a greater or less degree, is lost ; but 

 the gain can not be exclusively attributed to the principle of compensation; 

 for there is no close parallelism between the increased size and vigor of the 

 offspring and their sterility. Moreover it has been clearly proved that mon- 

 grels which are perfectly fertile gain these same advantages as well as sterile 

 hybrids. 



I>"-BREEDING. 



In close relation to the subject last under consideration is that of 

 In-Breedino; — with reference to its advantao:es and the dang-ers that 

 attend it or result from its pursuit. Much is written and said on this 

 STibject, and every amateur is ready to propound his maxim as the 

 embodiment of all the current philosophy relating to that branch of 

 breeding science. Two general truths are known to exist touching 

 this question; first, that in -breeding seems to secure and fix the good 

 or desirable qualities in a given breed or class of animals, and second, 

 that in-breeding too closely causes degeneracy, and results in deterio- 

 ration and loss of quality; that this latter, if persisted in, is far-reach- 

 ing and almost unlimited in the extent of the injury which it will 

 achieve. 



To those who speak from actual knowledge of the subject derived 

 from experience and a study of the department in which they are 

 engaged, it is not an easy question in all cases to determine how in- 

 breeding shall be conducted in order that the best and most permanent 

 advantages may be gained in the way of infixing or so stamping the 

 qualities desired as to make them permanent and hereditarily trans- 

 missible in high degree, without, at the same time, in any way impair- 

 ing the vigor and higher quality of the nervous organism or the 

 physical stamina of the animal or family. 



The blood of animals seems like the air we breathe — the very use 

 of it contaminates it, and it requires new elements to restore the 

 purity and force which each successive draught absorbs from the 

 source of supply. Consanguinity is the hotbed in which all the blood 

 impurities of a race are brought to early maturity. 



Mr. Darwin has written a letter to the English Agricultural Gazette-, 

 from which I extract the following: 



Sexual reproduction is so essentially the same in plants and animals, that I 

 think we may fairly apply conclusions drawn from the one kingdom to the other. 



