50 OBSERVATIONS ON THE CUCKOO. 
maintain the reputation they had acquired, a few 
slight additions and corrections only having been 
made by more modern writers till the publication of 
Dr. Jenner’s interesting discoveries ; indeed almost 
the only facts in the obscure history of this singular 
species which seem to have been known with any 
tolerable degree of certainty, even towards the close 
of the eighteenth century, were that Cuckoos appear 
and disappear periodically, that the call from which 
they take their name is peculiar to the male, that the 
female lays her eggs in the nests of other birds, that 
those birds carefully bring up the young Cuckoo 
(which has a weak, plaintive chirp, and is very different 
in plumage from adults), and that it is generally ob- 
served to be the sole occupier of the nest. In this 
state the history of the Cuckoo remained, when Dr. 
Jenner, at the request of Mr. John Hunter, undertook 
to investigate its habits and economy; and in the 
course of his researches, which were conducted with 
great care and assiduity, he discovered a number of 
curious facts, scarcely less wonderful than the marvel- 
lous but visionary speculations of the ancients them- 
selves. The following brief abstract will serve to 
convey some idea of what his skill and industry 
effected. 
Dr. Jenner informs us that the first appearance of 
Cuckoos in Gloucestershire, where his observations 
were made, is about the 17th of April. The call of 
the male, which is well known, soon proclaims his 
