the wall became insupportable, and must inevitably 

 have destroyed the tender young, had not affection 

 suggested an expedient, and prompted the parent 

 birds to hover over the nest all the hotter hours, 

 while with wings expanded, and mouths gaping for 

 breath, they screened off the heat from their suffer- 

 ing offspring. 



A farther instance I once saw of notable sagacity 

 in a willow-wren, which had built in a bank in my 

 fields. This bird, a friend and myself had observed 

 as she sat in her nest ; but were particularly careful 

 not to disturb her, though we saw she eyed us with 

 some degree of jealous}'. Some days after, as we 

 passed that way, we were desirous of remarking how 

 this brood went on ; but no nest could be found, till 

 I happened to take up a large bundle of long green 

 moss, as it were carelessly thrown over the nest, in 

 order to dodge the eye of any impertinent intruder. 



A still more remarkable mixture of sagacity and 

 instinct occurred to me one day as my people were 

 pulling off the lining of a hotbed in order to add 

 some fresh dung. From out of the side of this bed 

 leaped an animal with great agility that made a most 

 grotesque figure ; nor was it without great difficulty 

 that it could be taken ; when it proved to be a large 

 white-bellied field-mouse with three or four young 

 clinging to her teats by their mouths and feet. It 

 was amazing that the desultory and rapid motions of 

 this dam should not oblige her litter to quit their 

 15 183 



