d, indeed, in its full strength, seems to
constitute a partial loss of individuality. Mates will suffer pain and
endure physical injury for each other or for their offspring to as great
an extent as if these constituted a part of themselves, and as if their
actions were performed in self-defence.

With this brief review of the philosophy of the ethical sentiments, we
may proceed to a consideration of the facts. While the rudimentary form
of the sentiment in question is manifest far down in the descending
grades of animal life, it expands into what we may fairly term love or
affection only in the higher forms. Romanes, in his "Animal
Intelligence," remarks: "As regards emotions, it is among birds that we
first meet with a conspicuous advance in the tenderer feelings of
affection and sympathy. Those relating to the sexes and the care of
progeny are in this class proverbial for their intensity, offering, in
fact, a favorite type for the poet and moralist. The pining of the
'love-bird' for its absent mate, and the keen distress of a hen on
losing her chickens, furnish abundant evidence of vivid feelings of the
kind in question. Even the stupid-looking ostrich has heart enough to
die for love, as was the case with a male in the Rotund of the Jardin
des Plantes, who, having lost his mate, pined rapidly away."

Among social and communal animals the sentiment of sympathy widens to
embrace all the members of the tribe, a characteristic which is very
strongly manifested in so low an organism as the ant. As an example of
this feeling among birds, Romanes quotes an interesting illustration
from Edward, the naturalist. The latter had shot and wounded a tern, but
before he could reach it, the helpless bird was carried off by its
companions. Two of these took hold of it by the wings and flew with it
several yards over the water. They then relinquished their burden to two
others, and the process continued in this way until they at length
reached a rock at some distance. When the hunter, eager for his prize,
pursued them, the sympathetic birds again took up their wounded
companion and flew off with it again over the water.

Abundant instances of this sentiment of social affection could be quoted
from the mammalia. It is by no means confined to members of a species,
but may extend to very unlike species. No one needs to be told of the
warm affection so often shown by the dog for its master, a love which
will lead it to dare wounds or d