532 MR. J. S. HUXLEY ON THE 
Courtship- Actions. 
Selous observed numerous bouts of shaking, which he refers to 
in various ways: ¢.g., ‘They front each other in the water, and, 
with their snaky necks reared up, ¢dter a little with the beak, or 
make little tosses of their heads in the air” (loc. cit. p. 341). 
He has not, however, attended accurately to the positions of ruff 
and ears. All that can be said is that his pair (or two pairs) 
of birds certainly went through the ceremony of shaking, and 
apparently in just the same way as the many pairs seen by me. 
As far as I can judge (though judging is difficult) they did not 
shake quite so often. The important thing to notice, however, 
is that they did shake, even when they were quite alone on the 
water. That either jealousy or choice of mates should be the 
immediate cause, or purpose, of the action is thus absolutely 
excluded. 
On p. 457 he says:—‘‘They front each other with reared necks 
in the way often alluded to; then, without tdter-ing, each throws 
up the head several times into the air, at the same time opening 
and closing the long, slender bill.” He obviously considers this 
as being different from the usual ceremony, and adds that he 
has seen the same action several times, though less pronounced. 
I think it probable, if not certain, that his eye was here simply 
caught by a somewhat more pronounced shake than usual, the 
process referred to as tdéer-ing being then what I should call a 
bout of languid shaking; but in the absence of further details 
one cannot be sure. 
A possible but rather rudimentary display ceremony is perhaps 
indicated on Selous’s p. 340:—‘Once, too, the male flies suddenly 
some way off over the water.” 
Then on p. 343 is described a very fine weed-trick and Penguin- 
dance. It started with a bout of shaking; then the hen dived 
and came up with a small piece of weed which she apparently 
dropped. Just before or just after the hen came up (probably 
before, to judge from my experience), the cock dived too, and 
brought up a large bunch of weed. They came face to face, 
and “all at once both leaped entirely upright in the water.” 
The hen took hold of the dangling end of the weed which the 
cock was carrying, and then they “chasséd,” “with little waddling 
steps” from side to side (in the case seen by me, the birds rotated 
slightly back and fro on their axis and did not actually move 
from side to side. I think Selous is mistaken: such an action 
as he describes would be impossible on open water). Finally 
they sank down again, the weed was dropped, and “the male sets 
off, full of intention, to the nest on the opposite shore.” After 
some time the act of pairing was gone through. This is im- 
portant as showing that this elaborate courtship-action may 
sometimes lead more or less directly to pairing, i.e. may act 
(more or less) as an excitant. 
Finally, I must just refer to two more scenes. (1) (p. 163) :— 
