ADAPTATION OF STRUCTURE TO HABITS. 
239 
The wings are attached so very far back to the long narrow 
body that it is very difficult for the bird to walk at all; 
the plumage seems extraordinarily soft in its texture, 
feeling as it does like silk to the touch; it is, however, 
in reality very hard and compact, and at the same time 
perfectly water-tight. The bill is long, deep, powerful 
and sharp at the edges, in addition to which in some 
species it is strongly serrated, the points of the saw-like 
notches being turned backwards ; the moderately long 
neck is remarkable for its suppleness. The feet and 
wings appear to be the most distinctive features as regards 
their structure; the first serving as oars and the latter 
more or less as fins, both being highly developed not¬ 
withstanding their dissimilarity. The tarsus is compressed 
at the side, the sharpest edge being presented to the 
front; attached to it are three or four toes, which are 
either partially or wholly webbed or lobated; these, how¬ 
ever, together with the web, are capable of being 
compressed into a very small compass. The wings are 
adapted for diving in proportion as they are diminutive 
in size, and hard of texture. The tail is in some species 
composed of long, broad, elastic feathers, in others it is 
exceedingly short; in the first case it makes an excellent 
rudder, in the last the feet perform this office. I need 
only take as examples two species of this numerous 
family to make myself understood—the Grebe and the 
Penguin. Both are remarkable forms, and unite in 
themselves the peculiarities of the whole family. 
The bodies of both these birds bear a strong 
resemblance to a long-necked ninepin, flattened above 
and below, standing on two legs and decorated on 
either shoulder with two flap-like appendages. The 
Grebe is covered with hard satin-like feathers, which take 
