THE NATURAL HISTORY OF SELBORNE. : III 
is soon altered; for then a want of food soon overbalances 
the repletion occasioned by a checked perspiration. I have 
observed, moreover, that some human constitutions are more 
inclined to plumpness in winter than in summer. 
When birds come to suffer by severe frost, I find that the 
first that fail and die are the redwings, fieldfares, and then the 
song-thrushes. 
You wonder, with good reason, that the hedge-sparrows, 
etc., can be induced at all to sit on the egg’of the cuckoo with- 
out being scandalized at the vast disproportionate size of the 
supposititious egg ; but the brute creation, I suppose, have very 
little idea of size, color, or number. For the common hen, I 
know, when the fury of incubation is on her, will sit on a 
single shapeless stone instead of a nest full of eggs that have 
been withdrawn: and, moreover, a hen-turkey, in the same 
- circumstances, would sit on in the empty nest till she perished 
with hunger. | 
I think the matter might easily be determined whether a 
cuckoo lays one or two eggs, or more, in a season, by opening 
a female during the laying-time. If more than one was come 
down out of the ovary and advanced to a good size, doubtless 
then she would that spring lay more than one. 
I will endeavor to get a hen, and to examine: 
Your supposition that there may be some natural obstruc- 
tion in singing birds while they are mute, and that when this 
is removed the song recommences, is new and bold: I wish you 
could discover some good grounds for this suspicion. 
I was glad you were pleased with my specimen of the fern- 
owl; you were, I find, acquainted with the bird before. 
When we meet I shall be glad to have some conversation 
with you concerning the proposal you make of my drawing up 
an account of the animals in this neighborhood. Your par- 
tiality towards my small abilities persuades you, I fear, that I 
am able to do more than is in my power: for it is no small 
