GENERAL PRINCIPLES OF BREEDING. 587 



between excess and deficiency, so that the " golden mean " may be 

 preserved, upon which, as in every other business, the best success 

 depends. While it is well known that animals too fat are not pro- 

 lific breeders, yet if the barrenness be not dependent upon disease, 

 it may be easily corrected by exercise, or a systematic reduction of 

 the system. Decrease of milk and a tendency to barrenness are the 

 frequent attendants upon a constitution which fattens readily. 

 Hence " show condition " is not good for breeding stock. 



Conditions of Prolific Breeding Ancestry also must 

 be taken into account, when fruitfulness is desired, because an an^ 

 mal coming fi-om a stock inclined to sterility, or infrequency of 

 offspring, will inherit a tendency in the same direction, and notably 

 the tendency to twin-bearing will be found hereditary. This i? the 

 repeated indication in the human family, shown by numberless ob- 

 servations, and sheep-rearers have an accepted notion, the result of 

 experience, that twin-lambs in sheep is encouraged by saving the 

 ewe-lambs which are twins. Culley, on " Live-Stock," records that 

 Teeswater ewes bring forth generally two lambs each, sometimes 

 three ; there are some instances of four or five, and the author cites 

 one case of a ewe which " when two years old in 1872, brought forth 

 four lambs; in 1873, five; in 1875, five; in 1876, two, and in 1877, 

 two, the first nine in eleven months. Among cattle a peculiarity 

 especially is shown when twin -calves are born, one male and the 

 other female; the female is barren and is called a free martin. 

 When both twins are of the same sex, there is nothing abnormal 

 about them. 



Peculiar Characteristics may Develop After Sev- 

 eral Generations It is the more important for the breeder to 

 acquaint himself with the antecedents of his animals, because pecul- 

 iarities of habit, shape or weakness, may recur in the descent after 

 the lapse of generations. As an illustration, Goodall records that 

 in Maine polled-cattle appeared in a herd thirty-five years after the 

 destruction of every one of that character, and notwithstanding that 

 every calf dropped on the farm in the meantime had developed 

 horns. It is indisputable that the repetition of peculiarities is the 

 expression of some definite law of physiology. It comes so uni- 

 formly, and has such an absolute creation where the ancestry is 

 traceable; but there is not sufficient data upon which to found any 

 definite rule. But it is certain that the animal is not the creation 

 of its immediate parents alone, but involves far more than this its 

 individuality carries with it the sum of the existencies of all its an- 

 cestors, and these are determinable by the relative strength of char- 

 acter, or the dominant force of such ancestry. 



Proper Age for Sire or Dam In youth the physical 

 energies are engrossed by the labor of perfecting the physical struc- 

 ture of the individual animal, and generative power is not aroused 

 so that it may have proper exercise; and so in age, when the physi- 

 cal functions are deteriorating, the faculty of reproduction will not 



