It is among fishes, in the scale of animal life, that jealousy first
makes its appearance, according to Romanes. But in animals "jealousy,"
be it that of a fish or a stag, is little more than a transient rage
at a rival who comes in presence of the female he himself covets or
has appropriated. This murderous wrath at a rival is a feeling which,
as a matter of course a human savage may share with a wolf or an
alligator; and in its ferocious indulgence primitive man places
himself on a level with brutes--nay, below them, for in the struggle
he often kills the female, which an animal never does. This wrath is
not jealousy as we know it; it lacks a number of essential moral,
intellectual, imaginative elements as we shall presently see; some of
these are found in the amorous relations of birds, but not of savages,
who are now under discussion. If it is true that, as some authorities
believe, there was a time when human beings had, like animals, regular
and limited annual mating periods, this rage at rivals must have often
assumed the most ferocious aspect, to be followed, as with animals, by
long periods of indifference.[16]