OF SELBORNE. 551 



made their first appearance about the 18th and 20th, and 

 once as early as the 12th of October, and remained in great 

 abundance until the beginning of March. 



" These phenomena awakened and alarmed my curiosity 

 as events entirely new and unheard of among the body of 

 Ornithologists, and induced me to be particularly exact and 

 attentive in my observations on every part of their conduct. 

 Early in the autumn vast multitudes of these martins con- 

 gregate in all parts of the town of Castillar, which is situate 

 on the summit of a precipice most singularly lofty and ro- 

 mantic, about twenty miles north of Gibraltar. Hence it 

 may be inferred that they build and breed on the inland 

 mountains of Andalusia and Grenada. But on the approach 

 of winter, when their summer habitations become bleak and 

 inhospitable (for all those mountains are then usually 

 covered with snow), they retreat to these warm shores, and 

 remain there till the snow is gone next spring. A few are 

 always to be seen about our hill by the middle of October, 

 shifting round to all sides of the rock at times to avoid the 

 wind. November 2, 1771, I saw several, with some young 

 ones among them sitting in groups, on the cliffs, where the 

 old ones came and fed them." 



Thus have I, for your amusement, according to promise, 

 sent you an extract concerning this new, and unnoticed 

 swallow, which my brother, with great propriety, in his 

 work has called Hirundo hyemalis / and has given several 

 particulars concerning it, and a description of it, too long 

 for the compass of a letter. 



Permit me just to hint to you, that I wrote to you some 

 time ago in answer to your last letter, which gave me much 

 satisfaction. 



I forgot to mention in the extract, that these winter 

 swallows usually leave Gibraltar about the beginning of 

 March, unless deep snows ,(as is sometimes the case, and 



1 In his twenty-second letter to Pennant (p. 102), and in the fifth 

 letter of the present series, the species is named hyberna. The above 

 name hyemalis possibly is a lapsus memoria.Ev. 



