1887. | NEW YORK ACADEMY OF SCIENCES. 87 
the matter of tacking. There would seem to be suggestions 
here of value. 
Regarding the theory brought forward by Prof. Trowbridge, 
which involves the supposition that certain muscles are attached 
to the primary feathers, or in some way to the manus, or its 
phalanges, that produce certain movements of rotation, it would 
seem plainly a matter of well-known anatomical structure, and 
therefore one to be instantly decided by reference to the parts 
in question. 
The primaries, like all other feathers, being dermal in origin 
and growth, as are homologous structures of the mammalia, 
namely, the claws, nails, horns, etc., have no use for muscular 
attachments. All such dermal organs alike are inserted in 
duplications of the skin from which they grow; the follicles 
furnished to each secreting the substance from which the feather 
is developed in one case, the nail in another, and scales and 
other peculiar dermal appendages in others. 
Movements which affect the primary quills are the result of 
power applied to the bones on which the quills are situated. 
The distal ends of the tendons are inserted in the manus. There 
is no movement in birds’ wings like those in the hand of mam- 
mals, the two principal ones are adduction, drawing the wing 
upon itself, and abduction, spreading its parts. 
There is an automatic movement in the dermis of birds and 
mammals, which causes the familiar condition of ‘‘ goose flesh; ” 
and this shrinking of the skin is the cause of the erection of 
feathers as seen in fowls at times. The wrinkling of the skin 
on the back of animals is due to the same cause, both the volun- 
tary and involuntary exercise of the unstriped muscular tissue, 
so-called, being the motors. 
PRESIDENT NEWBERRY remarked that the discussion included 
three quite distinct questions, which had been somewhat con- 
fused :—the problem of soaring flight, ascent by gyrating, and 
the interlocking of the primaries, which were to be deter- 
mined by observation and experiment. 
Pror. TROWBRIDGE, in closing the debate, claimed that he had 
demonstrated the existence of a tendon to open or expand the 
primaries, the discovery of a muscle in the manus to close the 
same, and arotary motion as the function of a special muscle 
which locked them. 
It was voted to adjourn to January 9th, 1888. 
