548 MR. J. S. HUXLEY ON THE 
9. April 17. 2.25-3.5 p.m. 
2.25. A pair were swimming about fairly close to each other, 
resting and preening by turns. 
2.28. The hen three times went into the Dundreary-attitude 
with short intervals between. 
2.35. After resting for some minutes, she barked five times in 
succession, and relapsed into the resting position, never, 
however, shutting her eyes. 
2.44. One bird swam off out of sight; the other barked several 
times. After a little bit the first one came back into view, 
and they both began preening themselves. 
2.50. Suddenly a third bird (sex ?) came swimming towards them, 
and when about thirty yards off went into the Dundreary- 
attitude, at the same time giving five long, loud, rolling 
barks. At once both birds of the pair put themselves into 
the same attitude,and faced round on the third Grebe, uttering 
at the same time a series of short, low, and quickly-repeated 
barks. The intruder changed its course a few points and 
went off towards the reeds; directly it was out of the way, 
the pair “ got up and shook.” The shaking, however, only 
lasted for a short time, and they then relapsed into their 
previous state of preening and swimming about. 
2.55. After they had swum out of sight and back again, I saw 
one of them (sex ?) go to one side in Dundreary-attitude, 
calling repeatedly, and on looking further afield discovered 
the reason for this in the shape of an intruding single 
bird (sex ?) (probably not the previous intruder) who 
was approaching in the same position and uttering the same 
ery, about thirty yards away. This single bird then dived 
and came up not six feet away from the other. They were 
now in an attitude I had never seen before—hbest de- 
scribed as the most hostile possible form of the “ Dundreary,” 
differing from the typical form chiefly in that the heads 
were not quite so low down. For some time they stayed 
thus facing each other, still, or moving a little forwards as if 
to attack, and then at once thinking better of it, and all the 
time giving the low, quick bark. Finally the second bird 
of the pair came up, giving a loud grinding trumpet-call, and 
then all of a sudden there was a great flying of all the three at 
each other, and at the end of it one bird went off, and two 
(undoubtedly the original pair) were left together ; they at 
once approached and shook; the shaking, however, only 
went on for a short time, and then, after a few minutes’ 
preening, I lost them. 
Here, twice over, it is obvious that the presence of a third bird 
has screwed excitement to the shaking-point ; the remarkable 
thing in both cases is, that the bouts of shaking thus induced 
should last so short a time, whereas on another occasion (April 16, 
1.30 p.m.) a similarly-induced bout ended very differently. 
