1887. | NEW YORK ACADEMY OF SCIENCES. 81 
red-shouldered hawks, having the integuments removed, the 
offices of several tendons were exhibited. One of these, he 
thought, seemed to act as a ‘‘stay” or ‘‘tie” to support the 
stiffened wing; another connected the two ends of the curved 
ulna like the ‘‘ tie-rod ” of a girder. 
He also read a list of soaring birds, chiefly hawks, which have 
emarginated primaries. 
Pror. J. A. ALLEN said the tendon regarded as a support or 
tie was the patagium, which gives a straight line to the front. 
border of the wing. ‘The structure and anatomy of birds’ wings 
were so well known that he thought it impossible that any mus- 
cles and tendons should have remained undiscovered by the 
anatomists. He thought the emargination of the primaries had 
little relation to soaring, as some birds remarkable for soaring 
flight were destitute of the feature, while many birds which did 
not soar possessed it. Some grouse had the primaries very much 
cut away. In some pigeons and some humming-birds the emar- 
gination was very pronounced. In some of the fly-catchers only 
the males possessed the feature. In genera, where the females 
lacked the emargination, the young males also lacked it. 
Mr. D. G. Exvior denied the possibility of the rotation of the 
primaries, while admitting the motions of spreading and closing. 
The muscles producing the former movements, he thought, were 
involuntary, being a part of the abduction or stretching of the 
wing. He thought the notches in the primaries, which were 
rather characteristic of the raptores, although variable within the 
same genera, had no connection with the soaring. 
Pro. TROWBRIDGE said that he did not claim any rotation of 
the primaries individually, or apart from the rotation of the 
manus. 
Mr. GrorGe B. SENNETT regarded the interlocking of the 
primaries as entirely a mistake. 
Mr, Ernest E. Tuompson, of Toronto, Canada, being invited - 
to speak, said that, as an ornithologist, he had given much atten- 
tion to soaring flight, and had spent much time on the Western 
plains watching, with a glass, the buzzards and hawks soaring, 
