We look upon all these alleged facts with distrust. Many of them are coincidences; others, we suspect, are false. It is obviously insufficient for our purpose to ascertain the qualities of the one generation which is born. We must also know to what circumstances the parent may have owed its peculiarity. We feel convinced that education more than any other circumstance has influenced the superior powers of the animals above alluded to, and there is no proof that the parent did not possess the same capabilities or natural powers as the offspring.
There are, on the other hand, innumerable instances which shew that acquired alterations of structure are not transmitted. How many men are there who have lost limbs and yet have produced children in no respect maimed. A quadruped without the fore-legs has borne entire young. A bitch in which the spleen had been extirpated had young possessing that organ. Men with only one testicle have sons with the usual number; and lastly, the people of nations, the males of which have been cir cumcised during hundreds of years, have chil dren with foreskins not a bit shorter than those of nations in which no such practice exists.
The breeding of domestic animals of dif ferent kinds, suited respectively to the various useful purposes for which they arc employed, is a subject connected with the present question of high practical importance; but unfortu nately, though some practical men have well understood the proper method to be pursued, it is to be regretted that the facts have never been reduced to general rules, and that the theory has been almost entirely neglected.
It is generally admitted as a fact proven that in the ox, horse, and other domestic animals the purer or less mixed the breed is, there is the greater probability of its trans mitting to the offspring the qualities which it possesses, whether these be good or bad. Economical purposes have made the male in general the most important, simply because he serves for a considerable number of females. The consequence of this has been that more attention has been paid to the blood or purity of race of the stallion, bull, ram, and boar than to that of their females ; and hence it may be the case that these males more frequently transmit their qualities to the offspring than do the inferior females with which they are often made to breed. But this circumstance can scarcely be adduced as a proof that the male, cwteris paribus, influences the offspring more than the female.
Bad as well as good qualities may be trans mitted, and, therefore, it is obvious that in endeavouring to improve any stock by engraft ing a good quality, the breeder must choose a male which, besides the requisite good quality, is free from those defects of the female which it is desirable to sink. Ile must also select a
male in the family of which the desired quality has been long resident. lie cannot engraft the quality all at once, but must endeavour to introduce it by frequent crossing.
In the horse, for example, the strength of bone and weight of muscle suitable for slow draught, the light frame and prodigious swift ness of the race-horse, and the intermediate or rather combined qualities of the carriage-horse, hack, or hunter, are all capable of being pro duced by proper attention to purity or mixture of breeds. The pace, speed, action, temper, courage, colour or quality of hair, and almost all other qualities may be increased, dimi nished, or altered by a judicious admixture of different races. So also the immense weight of beef and fat of the large ox, the flavour of the flesh, the abundance or richness of the milk of the cow, are subject to modification in every different breeding.
The economical breeder, then, while he has settled in his mind the object which he wishes to accomplish in any of his stocks, must hold in recollection that it is only by the combi nation and continued succession of good qua lities that he can ensure a permanent improve ment. He must not expect to he able to effect this by crossing the breed of an impure blooded or worn-out female with a male of superior qualities. Bad qualities may become as fixed as good ones, and a judicious selection of the good ones (as adapted for his purpose) ought to be his first and principal object.• A belief exists with founded, it is said, both on common observation and scien tific research, that frequent breeding in the same family, or what is commonly called breeding in and in, has the effect of deterior ating a race. There appears, however, much reason to believe that the opinion just now stated is founded in error. In a state of nature it not unfrequently happens, among those ani mals especially which do not pair, that the strongest males take precedence of the weaker, and naturally select the finest females (as occurs in the deer); but in a state of domes ticity this cannot always be the case, and inferior animals coming together give rise to inferior offspring ; hut, if in the farm-yard sufficient care be taken in the selection of the breeding males and females, it does not appear that near relationship has any effect in dete riorating the race, nor in impeding the trans mission of good qualities which may be found in males and females of the same family.