THIRD SEASON (1920): PRELIMINARY 35 
to be able to ascertain upon which dates the Cuckoo 
deposited her eggs. 
Yet again, if we were to see how many eggs a 
Cuckoo would lay in a season under ideal * con- 
ditions, it was necessary, having ascertained at what 
intervals, regular or otherwise, she laid, to use our 
best endeavour to arrange matters so that a new 
Meadow Pipit’s nest would always be in readiness 
for the Cuckoo upon the recurrence of every 
ascertained interval. 
In the strong hope that Cuckoo A would return, 
I was anxious to prevent any of the Meadow Pipits 
hatching prior to her advent, and so made pre- 
liminary searches of the common on May 2, 5, and 9, 
with the result that six clutches of Meadow Pipits’ 
eggs were found and taken. It subsequently 
transpired that the search had been completely 
effective, for no nests which then existed had 
escaped our notice. 
On May 15 the first egg of Cuckoo A was 
found in a Meadow Pipit’s nest, and from that 
moment onwards I resolved with increasing fervour 
as the season progressed to leave no stone unturned 
* “ Ideal,” that is, from a scientific point of view ; the 
conditions, as will be seen, were artificially created, and were 
abnormal from the Cuckoo's point of view. 
