376 NATURAL HISTORY 



about ten minutes before eight o'clock in the evening, 

 he discovered a great cluster of house swallows, thirty 

 at least, he supposes, perching on a willow that hung 

 over the verge of James Knight's upper pond. His 

 attention was first drawn by the twittering of these 

 birds, which sat motionless in a row on the bough, 

 with their heads all one way, and, by their weight, 

 pressing down the twig so that it nearly touched the 

 water. In this situation he watched them till he could 

 see no longer. Repeated accounts of this sort, spring 

 and fall, induce us greatly to suspect that house swal- 

 lows have some strong attachment to water, indepen- 

 dent of the matter of food ; and, though they may not 

 retire into that element, yet they may conceal them- 

 selves in the banks of pools and rivers during the 

 uncomfortable months of winter. 



One of the keepers of Wolmer Forest sent me a pere- 

 grine falcon, which he shot on the verge of that district 

 as it was devouring a wood-pigeon. The Falco pere- 

 grinus, or haggard falcon, is a noble species of hawk 

 seldom seen in the southern counties. In winter, 17G7, 

 one was killed in the neighbouring parish of Faringdon, 

 and sent by me to Mr. Pennant into North Wales 2 . 

 Since that time I have met with none till now. The 

 specimen mentioned above was in fine preservation, 

 and not injured by the shot; it measured forty-two 

 inches from wing to wing, and twenty-one from beak 

 to tail, and weighed two pounds and a half standing 

 weight. This species is very robust, and wonderfully 

 formed for rapine : its breast was plump and muscular; 

 its thighs long, thick, and brawny ; and its legs remark- 

 ably short and well set : the feet were armed with most 

 formidable, sharp, long talons : the eyelids and cere of 

 the bill were yellow ; but the irides of the eyes dusky ; 

 the beak was thick and hooked, and of a dark colour, 

 and had a jagged process near the end of the upper 



8 See my tenth and eleventh [and twelfth] Letters to that gentleman. 



