Observations on the Cuckoo. 453 
and this is probably near the truth. In fe- 
males opened when they had just begun to 
lay, only four or five eggs were usually dis- 
covered, that could possibly be laid in sue- 
cession ; from the smallest of which, to what 
may be termed the secondary eggs, there was 
a sudden break off,—not a gradual decrease in 
size. The scarcity also of the eggs and 
young of this species, even in its favourite 
haunts, tends powerfully to confirm the opi- 
nion, that Mr. Jenner has greatly overrated 
its fecundity.* 
It is possible, that those cuckoos that arrive 
early may sometimes lay two sets of eggs 
during their stay with us; but then we may 
safely conclude, that a considerable interval 
of time always elapses between the produc- 
tion of the first and second sets; and it is 
quite as probable that those eggs which are 
occasionally found in July, should be laid by 
birds that arrive late, as by eariy coming 
birds that produce more than one set of eggs; 
for cuckoos come and go in succession, some 
individuals appearing three weeks, or even 
amonth before others: besides, it may fre- 
* White Moss, a bog of considerable exient, situated about four 
iniles to the N. E. of Manchester, isa very favourite resort of cuckoos ; 
yet the turf cutters inform me, that even in the most favourable seasons 
they never knew of more than five or six eggs belonging to this species 
in different nests at the same time, 
