THEORY OF GENERATION. 99 



CHAPTER VII. 

 THE PRINCIPLES OF BREEDING APPLICABLE TO THE flORSE. 



Theory of Generation In-and-in Breeding Out-Crossing , Advan 

 iages and Disadvantages of each Plan Causes of a "Hit" 

 Importance of Health and Soundness in both Sire and Dam 

 Best Age to Breed from Influence of Sire and Dam respectively 

 Choice of Sire and Dam The Kind of Horse most likely to be 

 Profitable to the Breeder Concluding Remarks on Breeding. 



THEORY OF GENERATION. 



THE IMPORTANCE of understanding the principles upon which 

 the breeding of the horse should be conducted is so great that 

 every one who superintends a stud, however small, should study 

 them carefully. To do this with advantage, he must investigate 

 the changes which take place after the union between the sexes, 

 and must endeavor to ascertain the influence which the sire and 

 dam respectively exert upon their offspring. 



In the year 1855. while engaged in preparing the article on 

 the breeding of the horse in " British Rural Sports/' I carefully 

 drew up the following epitome of the laws which govern the gene- 

 ration of the mammalia. Since then, the subject has constantly 

 been before me ; but, in spite of the numerous investigations car- 

 ried on by other observers, I have seen no reason to modify, in any 

 material degree, what I then wrote ; and I shall, therefore, to pre- 

 vent confusion, insert it entire, what slight additions may be neces- 

 sary being included within parentheses. 



1. THE UNION of the sexes is, in all the higher animals, neces- 

 sary for reproduction ; the male and female each taking their re- 

 spective share. 



2. THE OFFICE OF THE MALE is to secrete the semen in the 

 testes, and emit it into the uterus of the female (in or near which 

 organ), it comes in contact with the ovum of the female which 

 remains sterile without it. 



3. THE FEMALE forms the ovum in the ovary, and at regular 

 times, varying in different animals, this descends into the uterus, 

 for the purpose of fructification, on receiving the stimulus and ad- 

 dition of the sperm-cell of the semen. 



4. THE SEMEN consists of two portions the spermatozoa, which 

 have an automatic power of moving from place to place, by which 

 quality it is believed that the semen is carried to the ovum ; and 

 the sperm-cells, which are intended to co-operate with the yerm- 

 cell of the ovum in forming the embryo. 



5. THE OVUM consists of the germ-cell, intended to form part 



