Vol. xliii.] 54 



adequate data. He does not know how many egf^s his 

 Cuckoo has laid, nor where she has laid them. I suggest to 

 you that the value of the information derived from a study 

 of the exhibits of my Drawers Nos. 1, 2, and 4 — and per- 

 haps also a few others — is enormously enhanced for the 

 reason that the eggs represent the entire production in the 

 one case, and almost so in the other, of the Cuckoos in those 

 areas. 



Drawers Nos. 1 a^id 2 contain the whole of the sixty-one 

 eggs laid by the now famous Cuckoo " A " in the seasons 

 1918-21 inclusive, together with all the other Cuckoos' eggs 

 found on her territory during those seasons. On the right- 

 hand side of the second drawer will be found six other 

 C/Uckoos' eggs (five by one Cuckoo and one by another) found 

 on the same Common in the yeap 1916, two years before I 

 commenced my study. These eggs are interesting, in that 

 they prove to my satisfaction that my Cuckoo was not laying 

 here, at any rate, before 1917. The fact that in the year 

 1918 she allowed Cuckoo " B '' to share her territory makes 

 me feel pretty certain that in the year 1918 Cuckoo " A " 

 was in her first season. 



My reason for stating this is that I have yet to find two 

 Cuckoos tolerating each other on the same territory and using 

 the same fosterers concurrently for more than one season. 



Referring to Mr. Baker's seventh question as to " How 

 many, if any, of the fosterer's eggs do Cuckoos take ? " I 

 can assure you that in the years 1920 and 1921 the famous 

 Cuckoo " A " invariably took one egg, and only one, no 

 matter whether the nest contained one or more eggs ; as a 

 matter of fact, this Cuckoo showed supreme indifference (and 

 in this I think all Cuckoos are probably the same) as to the 

 contents of the nest, provided there was at least one fresh 

 egg there. Of her first twelve eggs in 1921 three were 

 laid in exchange for the single eggs in the nests of the 

 hosts, three more when the hosts' nests contained two eggs, 

 three when there were three eggs in the hosts^ nests, and the 

 other three when the fosterers' nests contained four eggs. 



If my theory is a correct one, that a dominating Cuckoo 

 (that is, a Cuckoo possessing a territory) finds her nests while 



