BIRD-HAUNTED LONDON 131 



the pair of them had gone off together, and he 

 returned without her with a caterpillar. He sum- 

 moned her to come to table — tee-tee-er, tee-tee-er — but 

 she responded not, and he dropped in to look for 

 her, and came out two minutes later visibly dis- 

 concerted, called loudly, planted his head in the 

 entrance hole and shouted again. But she came 

 not, and so, swallowing his caterpillar like a sen- 

 sible bird, he rushed off at full speed, crying out 

 to her in obvious concern. The way in which their 

 lives worked in fitness both to physical necessity and 

 emotional beauty was very seductive. When the 

 male was long absent, she used sometimes to put 

 her head out of the window, peering here and there, 

 and then disappear into her nest. This she would 

 repeat, if he still failed to put in an appearance. 

 The food was exclusively caterpillar or aphides, and 

 both birds refused to touch oatmeal, of which they 

 are very fond in autumn and winter. 



When the young were hatched, the labour of these 

 small birds to feed them became heroic, and they 

 both grew visibly thinner. 



Work apace, apace, apace, apace, apace. 

 Honest labour wears a lovely face. 



I could never understand how the young became aware 

 of one of their parents' visits before he or she went 

 into the nest. But they invariably began clamouring 

 in muffled, silvery chorus as soon as he or she 

 alighted, whether on top of the box or on a twig 

 within a foot of it — as they often did for an inspec- 

 tion. Could they have heard the foot alighting or 

 the wings beating ? Young birds are highly educable, 

 and are not born with too burdensome a luggage of 

 inherited adaptations — the most wonderful of them 

 all, the egg-tooth, an adaptation from reptilian an- 

 cestry, being an elaborated tool for one stroke and 

 then lost — but this superacute sense of hearing is one 

 that might very well be an over-specialization and 

 hence a danger to the species. For if an enemy 



