534 MR. J. S. HUXLEY ON THE 
(2) May 3rd. After this attempt the hen continued to sit ; the 
cock returned at intervals, and at one of his returns Selous 
noticed the hen assume the passive position. (Here there is 
again, perhaps, an error of omission. See the next entry.) 
(3) May 4th. The hen was sitting; the cock approached at least 
seven times, and at each approach the hen went into the 
passive position. In these last two cases (2 and 3) the cock 
paid no particular attention to the hen, save for the mere 
fact of his approaching the nest. 
(b) Both birds close to the nest. 
(4) May 21st. The birds were resting after having built most of 
a second true nest; they then began building again, and 
after about a quarter of an hour the hen jumped up on to 
the nest and assumed the passive position. The cock made 
no response. She soon came off, and the building went on. 
(5) May 22nd. Almost exactly the same scene as (4) on the 
previous day. 
(c) Both birds approach the nest together from a distance. 
(6) May 23rd. (Not recorded which bird led the way.) The 
hen assumed the passive attitude on the water; when she 
stopped the cock did the same, but remained in the attitude 
longer. 
(7) May 23rd. After (6) there was a pause of about forty 
minutes, during some of which the cock (alone) added to 
the nest; he then ascended the nest and assumed the 
passive attitude. The hen came up several times, and each | 
time acted as if about to leap up into the active attitude. 
Meanwhile the cock rose once or twice and then sank down 
again into the passive attitude. Finally he gave it up and 
took to the water. 
(8) May 23rd. After (7) there was a pause of a few minutes, 
during which the birds separated and went quite far afield. 
Then the hen ascended the nest and assumed the passive 
attitude. The cock came up, behaved just as the hen had 
done before (in 7), but finally leaped up, and there was an 
attempt to pair. 
[I have put (6), (7) and (8) together because each one seems 
to lead up to the next. If we were to separate them strictly, 
(7) should be under heading (b), for the birds remained fairly 
close to the nest all the time between (6) and (7). | 
(9) May 23rd. Nearly an hour later. This has been already 
described (p. 503). The hen incited the cock by lying along 
the water ; the cock responded by also going into the passive 
attitude ; the hen ascended the nest and assumed the passive 
attitude, and the cock then attempted to pair. 
Thus, in 1900, the three actual attempts at pairing were made 
