POUL TRY-CRAFT. 145 
that all variations except the small number coming in class 3, are due to 
‘inheritance; for it is a matter of common information that offspring do not 
inherit equally from both parents; that offspring of the same parents do not 
inherit alike; and that inheritance is not the transmittance of qualities from 
one generation to the next in a lump, — but goes back, ‘‘ takes back” through 
several of the nearest generations, and in less degree to more remote genera- 
tions. Now if the law of inheritance accounts for likenesses, slight differences, 
and a part of the greater differences, including some unusual, new, qualities, it 
is to be expected that it can account for so-called ‘‘ spontaneous” variations, 
which are simply variations of which the causes are not immediately apparent. 
Further, the law of inheritance requires that such phenomena of heredity as 
these spontaneous variations shall occur from time to time, just as imperatively 
as it requires that they shall take place only at long intervals. There is no 
place in this work for an extended demonstration of this proposition. It can, 
perhaps, be made sufficiently clear in a few words. 
Some observed facts of heredity, observations of the number of generations 
required to establish, “‘ breed in,” a desirable trait, or to ‘*breed out” an 
undesirable one, give the general rule :—.A descendant inherits one-fourth of 
the total of his qualities from each parent, one-sixteenth from each grand- 
parent, one-sixty-fourth from each great-grand-parent, one-two hundred 
and fifty-sixth from each great-great-grand parent. To put it another 
way: an individual, a fowl, may inherit an appreciable fraction of its qualities 
from each and every one of thirty ancestors, representing possibly the extremes 
of divergence from the breed type in a dozen different respects. The number 
of inheritable qualities is very great. The number of possible variations due 
to inheritance is enormous, practically infinite. The mathematical rule based 
on a few facts of inheritance teaches that slight variations should be very 
numerous, considerable variations more rare, and that at long intervals 
remarkable variations due to a fortuitous combination of two obsolete qualities, 
or of known and obsolete qualities, should occur. And since the law of 
inheritance, of the transmission of qualities, can explain the transmission of. 
unlike as well as of like qualities, it is neither sensible nor scientific to 
attribute a few phenomena to some other mysterious cause. The breeders’ 
maxim, ‘ Like begets like,” is literally true, and applies to differences as well 
as to resemblances. Every principle of breeding must conform to the law 
of inheritance. Every phenomenon of reproduction can be explained in 
accordance with the law, when @d/ the the facts are known. 
195. What the Law of Inheritance Is, and What It Means to the 
Poultry Breeder.— The law of inheritance is a zatural law; it simply 
expresses the relation between descendant and ancestors. It does not, and 
cannot show how heredity can be so controlled as to effect the direct trans- 
mission of such particular qualities as thé breeder esteems, and the immediate 
suppression of all others. As this is precisely what the poultry breeder would 
like to learn how to do, of what value is such a law to him? Just this: the 
