| → of structure often appears, 1860 1861 1866 1869 1872 |
| appears not unfrequently, 1859 |
|
| → quite unknown; no 1859 1860 1861 1866 |
| for the most part unknown. No 1869 1872 |
|
|
Any variation which is not inherited is unimportant for us. But the number and diversity of inheritable deviations of structure, both those of slight and those of considerable physiological importance,
endless. Dr. Prosper Lucas's treatise, in two large volumes, is the fullest and the best on this subject. No breeder doubts how strong is the tendency to
produces like is his fundamental belief: doubts have been thrown on this principle
theoretical
When
deviation
→of structure often appears,
and we see it in the father and child, we cannot tell whether it may not be due to the same
cause
on both; but when amongst individuals, apparently exposed to the same conditions, any very rare deviation, due to some extraordinary combination of circumstances, appears in the parent — say, once
several million individuals — and it reappears in the child, the mere doctrine of chances almost compels us to attribute its reappearance to inheritance. Every one must have heard of cases of albinism, prickly skin, hairy bodies, &c., appearing in several members of the same family. If strange and rare deviations of structure are
inherited, less strange and commoner deviations may be freely admitted to be inheritable. Perhaps the correct way of viewing the whole
would be, to look at the inheritance of every character whatever as the rule, and non-inheritance as the anomaly. |
|
| The laws governing inheritance are
→quite unknown; no
one can say why
peculiarity in different individuals of the same species,
in
different species, is sometimes inherited and sometimes not so; why the child often reverts in certain
to its
or grandmother or
more remote ancestor; why a peculiarity is often transmitted from one sex to both sexes, or to one sex alone, more commonly
|
