INDIRECT BENEFITS DERIVED FROM INSECTS. 291 



always on the wing hawking for them, and their flight 

 is regulated by that of their prey. When the atmo- 

 sphere is dry and clear and their small game flies high, 

 they seek the skies ; when moist and the insects are low 

 or upon the ground, they descend and just skim the 

 surface of the earth and waters ; and thus by their flight 

 are regarded as prognosticating fair or wet weather. 

 I was last summer much interested and amused by ob- 

 serving the tender care and assiduity with which an old 

 swallow supplied her young with this kind of food. My 

 attention was called to a young brood, that having left 

 their nest before they were strong enough to take wing, 

 were stationed on the lead which covers a bow window 

 in my house. The mother was perpetually going and 

 returning, putting an insect into the mouth first of one 

 and then of the others' in succession, all fluttering and 

 opening their mouths to receive her gift. She was 

 scarcely ever more than a minute away, and continued 

 her excursions as long as we had time to observe her. 

 When the little ones were satisfied they put their head 

 under their wing and went to sleep. The number of 

 insects caught by this tribe is inconceivable. But it is 

 not in summer only that birds derive their food from 

 the insect tribes : even in w inter the pupae of Lepi- 

 doptera, as Mr. White tells us, are the grand support 

 of those that have a soft bill*. 



I shall close my list of the indirect benefits derived 

 from insects, by adverting to the very singular apparent 

 subserviency of some of them to the functions of certain 

 vegetables. 



' White's SeBorne, 106. 



U 2 



