Food. 
408 NATATORES. COLYMBUS. Diver. 
abounding on all the interior lakes of the Fur Countries, 
but not often seen either in the Arctic Seas or in Hudson’s 
Bay.—Its principal food consists of fish, though it also de- 
vours aquatic insects, and 'Tremmincx adds marine vegetables; 
but I never found any remains of the latter in the stomachs 
of those I have dissected. When inhabiting the ocean, the 
different species of herring (as I have before remarked), are 
a favourite food; other small fish, however, are not refused, 
and Monracu mentions one that was gorged with the spotted 
goby (Gobius minutus.) Its powers in swimming and diy- 
ing are very great, particularly the latter, which it is con- 
stantly exercising, either in pursuit of prey or to escape ob- 
servation ; and its progress in this manner, from my own 
observations (corroborated by Monracu’s statement respect- 
ing the Red-throated Diver), may be calculated at more 
than seven miles in the hour. It generally proceeds for a 
hundred or a hundred and fifty yards at a time without ris- 
ing for respiration, which is then almost instantaneously ac- 
complished by the mere exposure of the head and bill. In 
swimming, the body is not visible, being under water from — 
its weight and flatness, and this situation enables it to dive 
with little apparent exertion, the depression of the head, and 
a slight propulsive effort with the feet, being sufficient for 
that purpose. The construction of the legs of this genus, 
and that of Podiceps (as I have before observed), is such as 
to disable them from walking; the backward position and 
confined action imposed by the close connexion of the tibia 
and femur with the body, caused by the covering of the in- 
teguments, and the attachment of a long process at the head 
of the tibial joint, necessarily producing this effect. In ad- 
dition to this, the femoral or thigh-bone is remarkably short, 
and stands at a right angle with the body, thus giving an 
outward direction to the feet, and only allowing a sub-rota- 
tory motion to the tibia, a mode of structure that, however 
beautifully adapted for the watery element, can be of little 
use upon land. The only method of progression, therefore, 
