By THE STORY OF THE BIRDS. 
its integrity were dying hard; for the papillw, or 
points out of which the feathers grow, rise up high, 
and long membranous sheaths follow the feathers out 
as much as an inch or more in some nestlings. 
By this rupture of the epidermis the skin ceased 
to build or secrete the outside skeleton or covering 
from the mere surface, but grew it from these papille, 
or pockets (representing the original folds), in the 
form of scales, feathers and fur. Only in the arma- 
dillos and a few rodents, where excess of material 
must have prevailed, did Nature in any high animal 
tend to return to a shell-like covering. 
How the soft condition of feathers and fur came 
about we can only conjecture, with hardly grounds 
for that; only we feel assured that it was at the de- 
mands of warmth. Hair may have been a fibrous 
breaking down of horny scales, since we know now 
that there is a very intimate relation between horns 
and hair. Some kinds of horns are made of hairs 
glued together, and nearly all horns are skin prod- 
ucts. 
Hairs, or similar plumous particles, may have 
arisen on the new scale as helpful in throwing off the 
old skin above it—a loosening agent. They are 
found now, it is said, performing this office in some 
snakes and crayfish. Here they dry down hard later. 
Possibly, after the skin was punctured by the scale, 
they may have grown out with it, and losing their 
use as skin looseners (since now the epidermis was 
broken up), they persist as part of the outer coy- 
ering. 
