pparently practising these duets in the intervals when the
parents are absent; single measured notes, triplets, and long concluding
trills are all repeated with wonderful fidelity, and in character these
notes are utterly unlike the hunger cry, which is like that of other
fledglings."

In such cases as those just enumerated, actual copulation is not
effected; but animals still sexually immature may perform coitus-like
acts, and Groos's work contains observations of these made by Seitz and
others. Seitz saw an antelope six weeks old making copulatory movements.
In young dogs such movements may often be observed, also in young
stallions and young bulls.

The view that in such cases the movements are imitative merely is
untenable, for young animals which have never had any opportunity of
watching the physical manifestations of love in older ones, will
nevertheless themselves exhibit such manifestations. At most it remains
open to dispute whether in these cases it is still permissible to speak
of love-games, as do Groos and others, or whether we should not rather
speak simply of manifestations of the activity of the sexual impulse.
But the dispute does not involve differences of opinion regarding
matters of fact; it is purely terminological. For, in the first place,
Groos himself, who regards the games of childhood as a form of training,
suitable to the nature of the individual, for its subsequent activities,
recognises that games are sexually differentiated. He believes that we
have to do, not, as some think, with imitative processes, but with
preliminary practice, subserving the purposes of self-development; and
he considers that girls naturally turn to games adapted to train them
for their subsequent profession of motherhood, whilst boys incline to
games corresponding to their predestined activity as men. Even if we
accept this theory of Groos, we are compelled to recognise a sexual
element in the games of youthful animals. In addition, however, we must
note the fact that Groos gives a wider extension to the concept of play
than other writers, and that he regards as love-games processes which
others might perhaps describe as sexual manifestations. According to
Groos, caressing contact is to be regarded as playful when, in the
serious intercourse between the sexes, such contact appears to be merely
a preliminary activity rather than an end in itself. Here two cases are
possible: in one the carrying out of the instinctive