 This same observer also relates that a well-known breeder bred a family of pigs in-and-in for seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and when...  The Breeding of Animals - 第 227 頁Frederick Blackmar Mumford 著 - 1917 - 310 頁完整檢視 - 關於此書
 | Charles Darwin - 1876 - 544 頁
...Improved Essex breed. Here is a more interesting case. Mr. J.Wright, well known as a breeder, crossed 2' the same boar with the daughter, granddaughter, and...straight. Now it deserves especial notice, that the two lust ROWS produced by this long course of interbreeding were sent to other boars, and they bore several... | |
 | 1896 - 606 頁
...seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and when attempting to move could not walk straight, until finally one sow was the sole offspring; she would not become pregnant by her sire, while to a... | |
 | T Warren O'Neill - 1880 - 482 頁
...Essex, and made the first great step towards the improved Essex breed. Here is a more interesting case. Mr. J. Wright, well known as a breeder, crossed the...straight. Now, it deserves especial notice, that the two best sows produced by this long course of interbreeding, were sent to other boars, and they bore several... | |
 | Albert Carey - 1880 - 222 頁
...authority * states that by strictly breeding in-and-in with pigs, the seventh generation in many instances failed to breed; in others they produced few that...and when attempting to move could not walk straight. Bates's herd of Shorthorn cattle was esteemed the most celebrated in the world, and though he had the... | |
 | Charles Darwin - 1887 - 528 頁
...so on for seven generations. The result was, that in many instances the offspring failed to brc-ed; in others they produced few that lived; and of the...of interbreeding were sent to other boars, and they lx>re several litters of healthy pigs. Tho best sow in external appearance produced during the whole... | |
 | Charles Darwin - 1892 - 558 頁
...in many instances tho offspring failed to breed; in others they produced few that lived; and of tho latter many were idiotic, without sense, even to suck,...could not walk straight. Now it deserves especial nolico, that tho two last sows produced by this long course of interbreeding were sent to other boars,... | |
 | 1896 - 764 頁
...generations ; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and when attempting to move could not walk straight, until finally one sow was the sole offspring ; she would not become pregnant by her sire, while to... | |
 | 1896 - 610 頁
...seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and. when attempting to move could not walk straight, until finallyone sow was the sole offspring; she would not become pregnant by her sire, while to a... | |
 | 1896 - 396 頁
...seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and when attempting to move could not \valk straight, until finally one sow was the sole offspring; she would not become pregnant by her... | |
 | Edward Fletcher Brush - 1898 - 154 頁
...seven generations; the number of pigs was reduced at each gestation, and of the offspring thus produced many were idiotic, without sense even to suck, and, when attempting to move could not walk straight, till finally one sow was the sole offspring. She was the handsomest of the entire seven generations,... | |
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