218 SITRENIA 
present at one time. The brain is remarkably simple in structure, 
its hemispheres exhibiting none of the richness of convolution so 
characteristic of the Cetacea. The mammary glands of the female 
are situated just behind and to the inner side of the origin of 
the pectoral limb. The red corpuscles of the blood are among 
the largest of those of any members of the class, averaging in 
diameter, according to Gulliver, zJyy of an inch. 
Manatees pass the whole of their life in the water, inhabiting 
bays, lagoons, estuaries, and large rivers ; but the open sea, so con- 
genial to the Cetacea, is quite unsuited to their peculiar mode of 
life. Asa general rule they prefer shallow water, in which, when 
not feeding, they lie near the bottom, supporting themselves on the 
extremity of the tail, or slowly moving about by the assistance of 
the fore limbs, the tips of which are just allowed to touch the 
ground, and only raising the top of the head above the surface for 
the purpose of breathing at intervals of two or three minutes. In 
deeper water they often float, with the body much arched, the 
rounded back close to the surface, and the head, limbs, and tail 
hanging downwards. The air in the lungs obviously assists them 
to maintain this position, acting in the same manner as that in the 
air-sac of fishes. Their food consists exclusively of aquatic plants, 
on which they browse beneath the water. They are extremely 
slow and inactive in their movements, and perfectly harmless and 
inoffensive. Frequent attempts have been made to keep specimens 
alive in captivity, and sometimes with considerable success, one 
having lived in the Brighton Aquarium for upwards of sixteen 
months. It was fed chiefly on lettuce and endive, but would also 
eat leaves of the dandelion, sow-thistle, cabbage, turnip, and carrot. 
From this and other captive specimens some interesting observations 
upon the mode of life of the animal have been made. One of these 
is the free use it makes of its fore limbs. From the shoulder-joint 
they can be moved in all directions, and the elbow and wrist permit 
of free extension and flexion. In feeding these creatures push the 
food towards their mouths by means of one of the hands, or both 
used simultaneously, and any one who has seen these members thus 
employed can readily believe the stories of their carrying their 
young about under their arms. Still more interesting and quite 
unique among mammals is the action of the peculiar lateral pads 
formed by the divided upper lip, thus described by the late Pro- 
fessor Garrod: “These pads have the power of transversely 
approaching towards and receding from one another simultaneously 
(see Fig. 73, Aand B). When the animal is on the point of seizing 
(say) a leaf of lettuce, the pads are diverged transversely in such a 
way as to make a median gap of considerable breadth. Directly 
the leaf is within grasp the lip-pads are approximated, the leaf is 
firmly seized between their contiguous bristly surfaces, and then 
