262 Huxley, Bird-watching and Biological Science. [july 



(6) Does either courtship or coition go on after the laying of the 

 first egg, or all the eggs? (We would expect both to go on till all 

 are laid, but not many facts have been collected on this head.) 



(f) Incuhation and Care of the Young: (1) Do both sexes share 

 in incubation? and if they share, do they share equally? (It is in- 

 teresting to find the cocks of some species with marked sexual di- 

 morphism sharing the duties of incubation; e. g. Ostrich, Blackcap 

 (Sylvia atricapilla). This latter, in addition to possessing a black 

 head distinguishing him from the brown-capped hen, is one of the 

 four or five best European songsters, and is reported by many 

 authorities to sing while actually brooding the eggs! In some cases 

 where the sexes share, the cock takes less of the duty, e. g. a friend 

 has told me that in case of danger near the nest, the cock Crested 

 Grebe will not go and sit himself, but yet will attempt to drive the 

 hen back.) 



(2) Do both sexes share in feeding the young? and if so, do they 

 share equally? (Here too we get indications that the male's 

 assistance is a comparatively recent development of evolution. 

 He is often not quite so bold or assiduous as the female. Old 

 Colonel Montagu brought a Goldcrest's nest from its natural situa- 

 tion, first on to his window-ledge, and then into his room; the male 

 had continued to help feed the young while the nest was on the 

 outside of the window, but refused ever to enter the room; but 

 the hen remained as assiduous as ever, and succeeded in rearing 

 the brood.) 



(g) General Miscellaneous Notes: Nothing much need be said 

 on this head. It is always well to remember that some actions of 

 birds seem to be gone through simply for the sake of releasing energy 

 in a pleasurable way, simply because the bird enjoys doing them. 

 Gulls, for instance, in early Spring fly round in aerial evolutions, 

 now solitary, now social; I have seen Wagtails (Motacilla lugubris) 

 in bright days in Autumn dart and run over the lawn and sing as if 

 possessed. In neither case was there the least connection with 

 courtship. In addition, some actions which have been developed 

 in evolution as part of courtship may be used to liberate energy 

 thus pleasurably (cf. from a similar point of view, children singing 

 and dancing when they are happy. They may do it spontaneously, 

 and then the sound or motion will be haphazard; but if they have 



