A BIRD’S NEW SUIT. 41 
upon food, climate, and environment generally. It 
may be shown also that color depends upon the same 
thing, since some birds that have color in the wild 
state, show no tint of it when confined. Color and 
molt, therefore, may in part have come out of the 
same conditions. 
Their development, however, has been so gradual 
that the maturity of the birds frequently outruns the 
maturity of the apparel, and they marry and rear 
families while yet in their baby clothes. 
Since there is such an intimate relation, as can be 
noticed in any animal, between vigor and color, it can 
be seen how unknown physiological agencies (such 
as congestions brought about by pressure, use, etc.) 
may have been set up which have produced changes 
in the whole texture and life of the feather through 
conditions of the feather-growing follicle or pocket. 
Out of this crests, plumes, and other abnormal struc- 
tures, along with the presence or absence of pigment, 
may have come; and they may have been subsequent- 
ly intensified by selection and heredity. Thus it is 
well known that if the skin follicles of a colored 
bird or mammal be injured at a certain place the 
feathers or hairs come in there again white; that if 
an ostrich plume be twisted in pulling, thus twisting 
the pocket, a twisted plume will ever after grow from 
it; that if certain parts of the skin of some birds be 
anointed with certain substances the feathers at the 
next molt come in having a different and abnormal 
color; and that the Javanese and other Eastern peo- 
ples have learned the art of preventing the molt of 
