230 BRITISH BIRDS. [vol. xiv. 



favourable to the production and discov^ery of such a lengthy 

 series. 



When the detailed information gathered during the daily 

 observations is published as a whole it will, I believe, throw 

 further light upon many points in connection with the Cuckoo 

 which have not been touched upon in this paper. It will also, 

 of course, amplify and analyse the incidents which have now 

 been but briefly referred to. 



For the season now close upon us we are hoping that this 

 Cuckoo will come back to the common to be observed for the 

 fourth time, but this of course depends upon how she may 

 have fared in her winter quarters and on her long journeys 

 to and fro. Should she return, and also the Meadow-Pipits 

 in sufficient number, we have already made arrangements 

 with the object of endeavouring to obtain a series of photo- 

 graphs of the bird in her most interesting moments ; and we 

 are not without hope of securing some convincing cinemato- 

 graph records of her operations. Our knowledge of the ways 

 of this Cuckoo, together with the nature of the ground, should 

 materially help towards the successful issue of our efforts in 

 this direction. 



In the meanwhile I should be very pleased to hear (at 9, 

 Hay Hill, London, W.i.), from anyone who might have a 

 suggestion to offer in regard to the making of some particular 

 observation. I mention this with the idea that we may per- 

 haps have the opportunity to be helpful to those who may 

 be pursuing a special line of inquiry and may possibly, in the 

 coming season, not succeed in meeting with a Cuckoo under 

 such favourable conditions as we are likely to do. 



Some of the conclusions to be drawn from the observations 

 made are : — 



(a) Under exceptionally favourable conditions a 

 Cuckoo can and will lay up to twenty-one eggs in one 

 season, and will deposit nearly all of them at intervals 

 approximating to forty-eight hours. This is not to say 

 or even imply that she lays a large number of eggs under 

 normal circumstances. 



{b) As this Cuckoo confined her operations to one 

 territory, it is a fair assumption that this is the general 

 action of Cuckoos. As to this there is, of course, a great 

 volume of other evidence. 



(c) Many Cuckoos show a strong tendency to be 

 parasitic upon one species, probably that by which she 

 herself was reared, her natural fosterer. With only one 

 exception, and that a very closely allied species in the 



