102 BULLETIN 107, UNITED STATES NATIONAL MUSEUM. 
to aid them in climbing-—as I frequently saw them do. The wearing of the 
lower edge of this mandible leaves a horny scalelike plate on each side of the 
mandible, with its lower edge free and easily scaled away in small fragments, 
The inclosed angle of the mandible is now a soft cartilaginous projection, 
which shrivels and reduces the size of the beak at that point. Next the horny, 
beadlike rim along the base of the upper mandible gradually loosens at each 
end below, and at the same time becomes freed from its attachment to the 
mandible, leaving a deep sulcus between, exactly as if done by a skillful cut 
with a scalpel. This beadlike rim now forms a part of the skin of the head 
and moves as such, perfectly independent of the beak. Then the narrow piece 
of sheath between the nares and the cutting edge of bill loosens and scales off. 
The entire base of the mandible is now in an exfoliating state and scales 
away, working toward the point of the beak. The narrow piece along the 
frontal line is pitted—each pit marking the position of a feather, as is shown 
in many cases where minute feathers are present. When this horny cover is 
removed a callous membrane bearing feathers is exposed, and these feathers 
extend up and pierce the fallen scale. The basal angle of the lower mandible 
becomes pliable before the horny cover breaks, and a dark suffusion shows as 
though a watery fiuid had exuded between the horny sheath and the cartilage. 
Food——Early in the morning many of the puffins, nearly all of 
those that are not incubating, leave their breeding grounds and fly out 
to sea in search of food; they may be seen going and coming more 
or less during the day, with their bills full of small fish for their 
mates or for the young; at night they all return. Their food con- 
sists mainly of small fishes, such as sand lances, sticklebacks, and 
smelt. Mr. Turner (1886) says: 
Their food is composed of mollusks of various kinds, a few shreds of certain 
seaweed fronds, and larvae, which are abundant on some of these seaweeds. 
Behavior—Pufliins play the part of the clown among birds; their 
appearance is comical in any attitude, and their movements are 
ludicrous enough as they walk about on their toes, in a semierect 
position, with a droll dignity peculiarly their own, or stand peering 
out of their nesting burrows, with an air of stupid inquiry. They 
are certainly fantastic combinations of the solemn and the burlesque. 
They are much at home on the rocks, where they are very active on 
their feet, walking or running with ease. When launching into the 
air off the rocks they glide swiftly downward with feet widely 
spread, sweeping in a wide circle out over the water and returning 
soon again to fly past or over the point from which they started. 
They seem to be impelled by curiosity or by their attachment to their 
homes to repeat this flight maneuver over and over again, flying in 
a large circle or in an ellipse, out over the ocean and back again past 
the cliffs. Hunters take advantage of this habit to lie in wait for 
them and shoot them, but if too much molested they become more 
wary. They are very hard to kill, however, as they are very tenacious 
of life. Their flight is not particularly swift, but quite steady, strong, 
and protracted; the wings are moved very rapidly and constantly; 
