LIVE STOCK. 



167 



dlviduals closely related. When It in- 

 volves the breeding together of sire 

 and offspring or o£ dam and offspring 

 or of brother and sister, it becomes 

 inbreeding, or "breeding ia and in." 

 It is line breeding carried to its limits, 

 and of course possesses all the ad- 

 vantages and disadvantages of that 

 form of breeding carried to their ut- 

 most attainable degree. 



Forms of Inbreeding. 

 Three forms of inbreeding are pos- 

 sible among animals namely: 



1. Breeding the sire upon his 

 daughter, giving rise to offspring three 

 fourths of whose blood lines are those 

 of the sire. — a practice whioh, if fol- 

 lowed up, soon results in offspring 

 with but one line of ancestry, thus 

 practically eliminating the blood of 

 the dam. This form of breeding is 

 practiced when it is desired to secure 

 all that is possible of the blood of the 

 sire. 



2. Breeding the dam to her own son 

 or sons successively, thus increasing 

 the blood lines of the female side. 

 This form is practiced when it is the 

 dam's blood lines that are to be pre- 

 served and condensed. Both systems 

 are necessarily limited to the lifetime 

 of the individuals involved. Either 

 system can of course be approximated 

 by the use of granddaughter or grand- 

 son, which would by common consent 

 be called inbreeding, but relationship 

 more remote would generally be re- 

 garded merely as line breeding. 



3. Breeding together of brother 

 and sister, — a, form of inbreeding 

 which preserves the blood lines from 

 both sire and dam in equal propor- 

 tions. It is inferior to either of the 

 others as a means of strengthening 

 previously existing blood lines, but it 

 is freely employed when the combina- 

 tion has proved exceptionally success- 

 ful, virtually establishing a new type. 

 It has all the dangers of the other 

 two, and in a larger degree, because 

 we have practically no acquaintance 

 with the new combination, whereas in 

 strengthening the proportion of one 

 line of ancestry over another, whether 

 it be that of the sire or that of the 

 dam, we are dealing with previously 

 existing blood lines known to be har- 

 monious. 



Among plants there are two forms 

 of inbreeding, namely: 

 1. That in which the fertilization 



is -with pollen from another flower on 

 the same plant. 



2. That In which fertilization is \>j 

 pollen of the same flower. This, be- 

 ing hermaphroditic, is the clo««6t 

 imaginable inbreeding, and exceeda 

 anything that is possible with ani- 

 mals. 



Advantages of inbreeding. 



Nobody claims advantages in In- 

 breeding per se, but it is the acme of 

 line breeding, and when superior in- 

 dividuals are at hand it is the most 

 powerful method known of making the 

 most of their excellence. It is the 

 method by which the highest poseible 

 percentage of the blood of an excep- 

 tional individual or of a particularly 

 fortunate "nick" can be preserved, 

 fused into and ultimately made to 

 characterize an entire line of descent 

 on both sides 



If persisted in, the outside blood dis- 

 appears by the same law that governs 

 grading, and the pedigree is speedily 

 enriched to here an almost unlimit- 

 ed extent by the blood of a single ani- 

 mal, — ^in practice, generally that of the 

 sire. It is a method not so much of 

 originating excellence as of making 

 the most of it when it does appear, and 

 it is not too much to say that a large 

 proportion of the really great sires 

 have been strongly inbred. 



An inbred animal is of course enor- 

 mousfly prepotent over everything else. 

 Its half of the ancestry, being largely 

 of identical blood, is almost certain to 

 dominate the offspring. Inbreeding Is, 

 therefore, recognized as the strongest 

 of all breeding, giving rise to the 

 simplest of pedigrees, — ^an advantage 

 quickly recognized when we recall ttoe 

 law of ancestral heredity. In this re- 

 spect it is all that line breeding is and 

 more. 



A second advantage Is that soccess- 

 ful associations of characters are pre- 

 served intact and not shattered by 

 the infusion of new strains. If the 

 breeder were deaUng with but a sin- 

 gle character he could readily find its 

 equal, and there "would be little need 

 for inbreeding; but even if breeding 

 for but a single utilitarian character, 

 he always has at least two other*, 

 vigor and fertility, which must be in- 

 cluded in selection. In practice he 

 has many more, and a single indirid- 

 ual that contains all or most of :them 



