C U C U L U S. 
oftrich, which, in the torrid zone, depofits its eggs in 
the fand, and the heat of the fun accomplifhes the de- 
velopement of the embryos. It never lofes fight of them 
indeed, and guards them afiiduoufly ; but it has not the 
fame motives as the cuckoo to conceal its attachment, 
and therefore does not take all the precautions which 
might exempt it from farther folicitude. 
What feems to have aftonilhed fome naturalifts the 
mod, is that attention, termed unnatural, in the nurfe of 
the cuckoo, which neglefits its own eggs to cherifii thofe 
of a foreign, and even hoftile, bird. One of thefe, a 
very refpedfable ornithologift, has made a feries of ob- 
fervations on this l'ubjedl: he took the eggs of feveral 
final 1 birds out of their nefts, and in their place fubfti- 
tuted a fingle egg of a bird of a different kind, and not a 
cuckoo ; and he inferred from his experiments, that, in 
fimilar circumftances, birds will hatch no fingle egg but 
the cuckoo’s, which is therefore favoured by a fpecial 
law of the Creator. But this conclufion will appear pre¬ 
carious, if we attend to the following confiderations : i. 
The airertion being general, one contrary fail is fufficient 
to overturn it ; and for this reafon, forty-fix experiments 
made on twenty fpecies are too few. 2 . It would require 
many more, and thofe performed with greater nicety, to 
eftablifh a propofition which is an exception to the ge¬ 
neral laws of nature. 3. Admitting the experiments to 
be fufficiently numerous and accurate, they would be 
inconclufive, if not made precifely in the fame manner, 
and in like circumftances. For inftance, the cafe is not 
fimilar when the egg is left by a bird or dropped by a 
man, efpecially by one who is biafted to a favourite hy- 
pothefts; nay, the frequent appearance of a perfon will 
difturb the moft eager brooder, and even caufe her to 
abandon the education of a cuckoo, though far advanced. 
4. The fundamental affections of this author are not 
quite accurate ; for, though it feldom happens, yet the 
cuckoo fometimes lays two eggs in the fame neft. Fur¬ 
ther, he fuppofes that the cuckoo fucks all the eggs in the 
neft, or deftroys them fomehow, leaving only its own ; 
but this is not the fa6t; for there are inconteftible proofs 
obferved by perfons attached to no hypothefis, which 
are direflly oppofite to thofe related by the author, and 
entirely overturn his inductions.. 
1. A hen canary, which fat on her eggs and hatched 
them, continued to fit when two blackbirds eggs, brought 
from the woods, were put under her, though eight days 
afterwards; and the ineubation would have fucceeded if 
they had not been removed. 
2 . Another hen canary fat four days on feven eggs, 
five of which were her own, and two thofe of a petty- 
chaps; but, the cage being carried to the lower ftory, 
flie forfook them all. Afterwards fhe laid two eggs, but 
did not fit. 
3. Another hen canary, whofe mate had eaten her 
-feven firft eggs, fat on the two laft, along with three 
others, the one a canary’s, the fecond a linnet’s, and the 
third a bulfinch’s; but all thefe happened to be addle. 
4. A hen wren hatched a blackbird’s egg ; and a hen 
Jiedge-fparrow hatched a magpie’s egg. 
5. A hen hedge-fparrow fat on fix eggs which fire had 
laid; five were added, and file ftill fat; five more were 
added, and, finding the number too large, fhe ate feven 
of them, and continued to fit on the reft ; two were taken 
away, and a magpie’s egg put in their place, and the fpar- 
:row hatched it, along with the {even others. 
6. There is a well-known method of hatching cana¬ 
ries’ eggs, by putting them under a hen goldfinch, taking 
-care that they are previoully as far advanced in their in¬ 
cubation as thofe of the goldfinch. 
7. A hen canary having fat nine or ten days on three 
of her own eggs and two of thofe of the blackcap, one 
of the latter was removed, in which the embryo was not 
only formed, but living ; two young yellow buntings, 
juft hatched, were entrufted to her, and fhe treated them 
with the fame attention as Ike would do her own, and 
Vql. V. Fio. 283. 
ftill continued to fit on the four eggs that were left, but 
they turned out to be addle. 
8. About the end of April 1776, another hen canary 
having laid an egg, it was taken away ; and three or four 
days after, it being replaced, the bird ate it. Two or 
three days afterwards, flic laid another egg, and fat on 
it; two chaffinch’s eggs were then put under her, and 
Hie continued to fit, though flic had broken her own 
eggs; at the end of ten days the chaffinch’s eggs were 
removed, being tainted. Two newly-hatched yellow 
buntings were given, which (he reared very well. After 
this file laid two eggs, ate one, and, though the other 
was taken away, fhe continued to brood as if (lie had 
eggs; a fingle egg of the redbreaft was put under her, 
which flie hatched fuccefsfully. 
9. Another hen canary, having laid three eggs, broke 
them almoft immediately ; tw’o chaffinch’s eggs, and one 
of the blackcap, were fubftituted, on w hich (he fat, and 
on three others which file laid fucceffively. In four or 
five days, the cage having been carried to a room in the 
lower ftory, the bird forfook them. A fhort time after¬ 
wards (lie laid an egg, to which was joined one of the 
nuthatch, and then two others, to which a linnet’s egg 
was added. She fat on them all feven days, but, pre¬ 
ferring the two ftrangers,. ftie threw out her own fuccef¬ 
fively on the three following days, and the eleventh flitr 
alfo tolled out that of the nuthatch, fo that the linnet’s 
was the only one that fucceeded. If this laft egg had 
been that of a cuckoo, what falfe inferences might have 
been drawn ! 
10. On the 5th of June, a cuckoo’s egg was placed 
under the hen canary mentioned in the feventh experi¬ 
ment, which ftie hatched, along with three of her own. 
On the 7th, one of thefe eggs difappeared; another on 
the eighth, and the third and laft on the 10th ; on the 
nth, ftie alfo ate the cuckoo’s egg. Laftiy, a hen red¬ 
breaft, ardently bent on brooding, had been feen to unite 
with her mate in repelling a female cuckoo from the 
neft; they fcreamed, attacked furioufiy, and hotly pur- 
fued her. While one of the redbreafts was ftriking with 
its bill the lower belly of the cuckoo, this bird fliivered 
its wings with an almoft infenfible quiver, opened its bill 
fo wide that another redbreaft, which affailed it in front, 
drove its head feveral times into the cavity, without re¬ 
ceiving any injury ; for the cuckoo was no way irritated,, 
but feemed to be in the condition of a female under the 
neceffity of laying. In a little while the cuckoo, being 
exhaufted, began to totter, loft its balance, and turned 
on the branch, from which it hung by the feet, its eyes 
half fiiut, its bill open, and its wings expanded. Having- 
remained about two minutes in this attitude, conftantly 
harralfed by the two redbreafts, it quitted the branch, 
flew to perch at a diftance, and appeared no more. The 
female redbreaft then refumed her incubation, and all her 
eggs were regularly hatched. 
It follows from thefe experiments, 1. That the females 
of many fpecies of fmall birds which hatch the cuckoo’s 
egg, hatch likewife other eggs along with their own. 2. 
That they often fit on thefe eggs in common with their 
own, which they fometimes entirely deftroy. 3. That 
they will hatch a fingle egg, though it be not a cuckoo’s*. 
4. That they boldly drive off the female cuckoo, when 
they find her dropping the egg in their neft. 5. That 
they fometimes eat this favoured egg, even in cafes where 
it is fingle and alone. But a more general and important 
confequence is, that the inftinT of hatching, which fome— 
times appears fo powerful in birds, is not determined by 
the kind or quality of the eggs; fince they often eat or 
break them, or fit on addle ones; they fit even on balls 
of chalk or wood, and fometimes brood in the empty 
neft. When a bird hatches the egg of a.cuckoo, or of 
any other bird, fhe follows therefore the general inftinft ; 
and it is unneceffary to recur to any fpecial appointment 
of the Author of Nature in accounting for the conduct 
of the female cuckoo. The reader will pardon this long 
5. S- dilcuffion-, 
