68 Bolam: The Natural History of Hornsea Mere. 
seventh on the margin of the Round House reeds. There was, 
I think, yet another pair of birds on the Mere, and I can 
confidently say that at least seven pairs attempted to nest 
this year, and that five of them, at any rate, succeeded in 
hatching their young, despite the very unfavourable weather 
conditions. From these five, nineteen young were duly hatched 
and left the nests. Whether they all survived, or how many 
of them did so, it was impossible to say, as up to the time 
I left they never appeared to quit the shelter of the reeds, 
and it was only by long and patient watching that any of 
them were seen. I rather feared that at least some of them 
must have met an untimely end, but from his previous ex- 
perience Taylor looked forward with confidence to seeing 
them abroad after they had grown older.* It will not be over- 
looked, however, that, if they lived, the first-hatched brood 
must have been about nine weeks old by the z2oth July, 
another seven weeks, and the youngest of the five more than 
a month. 
I do not know what is the normal period of incubation 
with this species, nor whether that period is known to be lable 
to considerable fluctuation, depending perhaps on the tem- 
perature of the nest, climatic conditions, and so forth; but 
my experience with regard to three of the above nests was 
interesting. The’ first nest seen was in Heslop’s reeds, and 
this I watched the birds building on the afternoon of 21st — 
April. I rowed past the nest a few days later, but did not 
push into the reeds to interfere with it, as it did not appear 
to contain eggs, and I felt sure that it could not do so. On 
Ist May I went to look at it again, and then found that it 
contained four eggs, three rather dirty, one white, and, I 
concluded, therefore, fresh. I took some photographs. of it 
and left it. It was seen in the near distance from time to 
time during the next ten days, and incubation was proceeding 
in a normal manner, but on 12th May, when I took Mr. Booth 
to see it, the nest was found to be empty, and I feared some 
ill must have befallen the eggs. There was, however, nothing 
to suggest this, and the nest was a good deal paddled down, 
as though it had been recently occupied, and it still remained 
warmer than the surrounding water. I did not think there had 
been time for the young to have hatched, but it is almost 
certain that they were, for I do not think there was any other 
such early nest in the vicinity, and next day the 13th, when 
I spent a considerable time in watching the place; I saw two 
young grebes there with their mother, and no doubt there were 
* This expéctation was not fulfilled. On 12th November, Taylor 
writes me that he had only seen two young this year. 
Naturalist, 
