3 
Whils the hereditary qualities, or those. with which the creature is 
bern, count for a guod deal in an animal, and determine in the main what 
it will become, it has also to be admitted that animals are very plastic in 
their youth, and that the hereditary tendencies can be encouraged or re- 
strained by the conditions to which they are subject. sy high treatment 
of ostrich chicks the feather growth can be stimulated. and, with this 
foundation it 1s easier for the feather germs to continue to produce better 
feathers than it would be to start superior feather production in birds 
which had not attained it while young. 
It is not urged that the spadonas are an altogether reliable criterion 
or what the later feathers will be; there are many experiences to the con- 
trary; but it is maintained that in them part of the foundation is laid 
down which will determine the future clippings. 
This foundation is continued during the growth 
of the juvenal feathers and in the growth of the 
third crop; but from this time on very little 
advancement can be expected, a greater or less 
fixity having been reached with maturity. If 
a good feather has not been produced at the 
second-after-chicks, it is not likely to be grown 
afterwards; the feather-producing qualities of 
each socket have by that time become more or 
less settled, and both internal and _ external 
conditions will have much less effect than 
before. 
It it these considerations which impress one 
with the great need there is that chicks and 
young birds should be well treated, and main- 
tained in the best of conditions, even at con- 
siderable expense, in order to encourage their 
feather producing powers to their utmost; for 
once these have been developed and fixed, there 
is not the same likelihood they will change 
either for better or for worse. Even if the 
size of the adult plume is not determined by 
that of the spadona, it certainly is by that of 
the juvenal and second-after-chick. To get 
the best the bird can produce, the effort must 
be made from the beginning. 
Experience has proved, however, that an 
adult bird usually producing good feathers may 
occasionally give rise to a crop altogether 
inferior. Especially after an exceptionally 
good clipping it is sometimes found, for no 
reason which has yet been determined, that Fig. 1—An inferior twisted 
the next crop is almost valueless. A marked feather, one ofa complete clip- 
: ‘ ; ping, grown by a bird which 
bre fi s ) N ~) yNOCO - . 
case is that shown in the _ photopraph “eualiy produces  eupesier 
(Fig. 1). The clipping previous to the one feathers. 
from which the feather was obtained consisted 
of good plumes, and, although the bird apparently continued in the same 
condition of health, yet all the feathers were of the same worthless char- 
acter as that here shown. It is obvious there must have been some differ- 
ence in the featherproducing vigour of the bird during the growth of the 
two crops, but without having the bird under observation it would be im- 
possible to say in what the difference consisted. Granted that the bird 
was in the same condition of health on both occasions one can only surmise 
gome seasonal or sexual influence had reduced its physiological vigour. 
