d-hot irons
in the same place, transmit visible traces of such marks to their
colts.

Very curious are the facts which go to show that acquired habits
sometimes become hereditary. Pritchard, in his "Natural History of
Man," says that the horses bred on the table lands of the Cordilleras
"are carefully taught a peculiar pace which is a sort of running
amble;" that after a few generations this pace becomes a natural one;
young untrained horses adopting it without compulsion. But a still
more curious fact is, that if these domesticated stallions breed with
mares of the wild herd, which abound in the surrounding plains, they
"become the sires of a race in which the ambling pace is natural and
requires no teaching."

Mr. T.A. Knight, in a paper read before the Royal Society, says, "the
hereditary propensities of the offspring of Norwegian ponies, whether
full or half-bred, are very singular. Their ancestors have been in the
habit of _obeying the voice_ of their riders and _not the bridle_; and
horse-breakers complain that it is impossible to produce this last
habit in the young colts. They are, however, exceedingly docile and
obedient when they understand the commands of their masters."

A late writer in one of the foreign journals, says that he had a "pup
taken from its mother at six weeks old, who although never taught to
'beg' (an accomplishment his mother had been taught) spontaneously
took to begging for every thing he wanted when about seven or eight
months old; he would beg for food, beg to be let out of the room, and
one day was found opposite a rabbit hutch apparently begging the
rabbits to come and play."

If even in such minute particulars as these, hereditary transmission
may be distinctly seen, it becomes the breeder to look closely to the
"like" which he wishes to see reproduced. Judicious selection is
indispensable to success in breeding, and this should have regard to
_every particular_--general appearance, length of limb, shape of
carcass, development of chest; if in cattle, the size, shape and
position of udder, thickness of skin, "touch," length and texture of
hair, docility, &c., &c.; if in horses, their adaptation to any
special excellence depending on form, or temperament, or nervous
energy.

Not only should care be taken to avoid _structural defects_, but
especially to secure freedom from _hereditary diseases_, as both
defects and diseases appear to be more easily transmissible than
desirable q