OF SELBORNE. 179 



When brown owls hoot, their throats swell as big as a 

 hen's egg. I have known an owl of this species live a full 

 year without any water. Perhaps the case may be the 

 same with all birds of prey. When owls fly they stretch 

 out their legs behind them as a balance to their large heavy 

 heads : for as most nocturnal birds have large eyes and 

 ears they must have large heads to contain them. Large 

 eyes I presume are necessary to collect every ray of light, 

 and large concave ears to command the smallest degree of 

 sound or noise. 



It will be proper to premise here that the sixteenth, eighteenth, 

 twentieth, and twenty-first letters have been published already in the 

 " Philosophical Transactions :" but as nicer observation has furnished 

 several corrections and additions, it is hoped that the re-publication of 

 them will not give offence ; especially as these sheets would be very 

 imperfect without them, and as they will be new to many readers who 

 had no opportunity of seeing them when they made their first appear- 

 ance. G. W. 



The Hirundines are a most inofieasive, harmless, enter- 

 taining, social, and useful tribe of birds : they touch no 

 fruit in our gardens ; delight, all except one species, in 

 attaching themselves to our houses ; amuse us with their 

 migrations, songs, and marvellous agility : and clear our 

 outlets from the annoyances of gnats and other troublesome 

 insects. Some districts in the South Seas, near Guayaquil, 1 

 are desolated, it seems, by the infinite swarms of venomous 

 mosquitoes, which Uli the air, and render those coasts in- 

 supportable. It would be worth inquiring whether any 



a large number of beetles belonging to seven or eight different genera, 

 besides quantities of cock-chafers (Melolontlia vulgaris). In pellets 

 of the long-eared owl, he found remains of mice 14, voles 271, shrews 

 2, and small birds 3. Of the short-eared owl he examined only a few 

 pellets, which were found to contain the remains of water voles only, 

 but as these were obtained in a single locality where these animals were 

 especially abundant, he reserved his remarks on the food of this owl 

 until he could make further investigations. In the details, however, 

 which he has furnished, we have abundant proof of the important ser- 

 vices which owls render to the agriculturist. ED. 

 1 See " Ulloa's Travels." G. W. 



