PnaiTONID.® . BIRDS. GRACTJLIDffl. 
cciv 
but express an inability to comprehend it. Tlie I'act 
that tliese birds soar, or remain apparently motion- 
less, only when the wind is considerable, seems to 
have escaped their notice. For therein lies the 
secret. The 'J’achypetes represents the most spread 
of wing- and the least proportionate body of any 
bird, and is, conserpiently, one that possesses the 
greatest faculty for maintaining the curious position 
in mid-air. Another fact is, the bird always faces 
the wind. We have, then, the same conditions as in 
the case of a boy’s kite. 'I’he bird is well repre- 
sented by a kite. It rises precisely as a kite does, 
and it moves only as it does — not by any movement 
of feathers, but a gentle swaying, and a trifle of 
tilting on the wind, to maintain its balance. What 
keeps it I'rom being blown away — for the kite has its 
string? 'I'he intelligence of the bird causes it to tilt 
forward just enough to counteract the force of the 
wind, and thus the smallest possible space is pre- 
sented to the wind ; it is merely a thin edge. 'I'ip- 
ping forward causes the body to fall against the 
wind ; the two forces — gravity and the wind — are op- 
posed, and a perfect rest is the result. 'I'he writer 
received a note from Mr. Dai'win, in answer to one 
suggesting this explanation. Jn this answer he 
says: “I have thought of some such explanation, 
but the mathematicians say that it is not }) 0 ssible ; 
that the two forces do not operate in a direct line, 
opposite to each other.” Now, there is the qualify- 
ing power of buoyancy, which operates to prevent 
the bird from dropping directly down like dead 
weight. We must regard the bird as it is — a thin, 
exceedingly light olqect, that is kept up by a strong- 
wind, and that by its intelligent attention to keep 
the outspread wings and body rigid and always edge- 
wise to the wind, with a slight tendency downward. 
'I'liese conditions observed, the bird rests upon the 
wind, as the kite does, the force of gravity' operatiiig 
as the string. It is not uncommon to see a stifl' 
piece of paper balanced in air by the wind, and when 
inclined even directly against the wind, to shoot 
forward until it goes obliquely to the ground. Now, 
could this paper, just at the moment of falling, while 
inclined against the wind, act to tilt its face a trifle, 
the wind would send it backwards and upwards 
again. 'I'hus, if the two forces were opposed by in- 
telligent action, the result would be as in the bird, a 
complete balancing oil the wind. 'I'he very close 
range at which these birds were observed made it 
possible to determine that no movement whatever 
took place among the wing feathers. 
Family— PH /MrONlDyE. 
Tropic Birds. 
]5irds of this family seem to have been distin- 
guished by this name without any especial reason. 
'They are much like a stout 'I'erii in figure. 'I'he prin- 
cipal external characteristic is the development of 
the two middle tail-feathers into long jilumelets. 
TROPIC BIRD (Fhmton flnviroslris). — 'I'his is a 
beautiful white, satiny, rose-tinted bird, of graceful 
flight, and one that is especially regarded by sea- 
faring people as a friendly visitor and companion 
while at sea. It is rare with us, but is occasionally 
met with on the Florida shores. 
Family— GRACULID^. 
DOUBLE-CRESTED CORMORANT (Graculus dilo- 
phus) — commonly called Shag. — Inhabits the whole 
of North America, in the interior as well as coast- 
wise. In this respect it differs from all other spe- 
cies. Audubon records a variety (G. floridianus) as 
far north as Ohio, and Dr. Coues in North Carolina. 
It has been found breeding in Labrador and the Gulf 
of St. Lawrence, whence it migrates south in the 
fall, wintering along the coast of Maine to the Caro- 
linas. It has been noticed at Great Salt Lake, in 
the interior. It forms its nest of sea-weeds, sticks, 
moss, and clods of earth with grass adhering to 
them, which it piles up into a solid mass, often as 
high as three feet from the rock, with a diameter of 
eighteen inches at the top and of two and a half 
feet at the base. 'I'he whole has an appeaiance of 
solidity such as is seldom seen in nests of water- 
birds. 'I’he nests are placed as near each other as 
the nature of the ground will permit. 'I’he flight of 
this bird is strong- and well-sustained, although not 
so rapid as that of the Florida Cormorant. It sails 
at times in a beautiful manner, and at a great height 
over the waters. Like other species, they are fond 
of sunning themselves with their wings spread out. 
'They walk awkwardly, and cannot run except with 
their wings spread out. When rising to fly from the 
water, they are obliged to run and beat their wings 
on the surface for a time before they can rise. 'I’he 
length is, to the end of the tail, thirty-three inches ; 
extent of wing, fifty-one inches ; weight, five pounds 
and seven ounces. 
MEXICAN CORMORANT ((?.wea:tcamis).— 'I’his bird 
has a habitat in the Southern States and southward. 
It has been noticed up the Mississippi River as far 
as Illinois. It is also found in Cuba. 
COMMON CORMORANT {G. car Ju).— 'I’his bird is 
abundant on the Labrador Coast, where great numbers 
gather to breed. Its length is thirty-seven inches. 
It reaches as far south as New Jersey in winter. 
PALLAS’ CO'&'M.O'RA.^T {G. perspicillatus) is found 
in Russian America. Its length is thirty-six inches. 
THE TUETED CORMORANT {G. cincinnatus) is 
found on the North-west Coast, at Sitka. Its length 
is about thirty-six inches. 
BRANDT’S CORMORANT {G. penicillatus) is com- 
mon on the Pacific Coast of North America. Length 
about twenty-eight inches. 
THE VIOLET-GREEN CORMORANT {G. molacem) 
is only found on the West Coast, southward to Cal- 
ifornia. Its length is about twenty-eight inches. 
Family— LARIDvE. 
'I’he Gulls. 
THE SKUA {Stereo mrius slcua). — 'I'his bird has a 
habitat throughout the seas of North America, but 
chiefly in the more arctic regions. A variety, antarc- 
ticus, is found in the Southern Ocean. 
