MISCELLANEOUS OBSERVATIONS. 197 



Fields, and about Whitechapel. The question is, 

 where these build, since there are no banks or bold 

 shores in that neighbourhood ? Perhaps they nestle 

 in the scaffold-holes of some old or new deserted 

 building. They dip and wash as they fly sometimes, 

 like the house-martin and swallow. 



Sand-martins differ from their congeners in the di- 

 minutiveness of their size, and in their colour, which 

 is what is usually called a mouse-colour. Near Va- 

 lencia, in Spain, they are taken, says Willughby, and 

 sold in the markets for the table, and are called by 

 the country people, probably from their desultory, 

 jerking manner of flight, Papillon de Montagna. 



LETTER LX. 



TO THOMAS PENNANT, ESQ. 



SELBORNE, Sept. 2, 1774. 

 DEAR SIR, 



BEFORE your letter arrived, and of my own ac- 

 cord, I had been remarking and comparing the tails 

 of the male and female swallow, and this ere any 

 young broods appeared ; so that there was no danger 

 of confounding the dams with their pulli ; and, be- 

 sides, as they were then always in pairs, and busied 

 in the employ of nidification, there could be no room 

 for mistaking the sexes, nor the individuals of differ- 

 ent chimneys, the one for the other. From all my 

 observations, it constantly appeared that each sex has 

 the long feathers in its tail that give it that forked 

 shape ; with this difference, that they are longer in 

 the tail of the male than in that of the female. 



Nightingales, when their young first come abroad, 

 and are helpless, make a plaintive and a jarring noise; 

 and also a snapping or cracking, pursuing people 



