LETTER XL. 



the same. 



SELBORNE, Sept. ind, 1774. 



iAR SIR, Before your letter arrived, and of my 

 own accord, 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 besides, 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 different chimneys the one for the other. From all my observa- 

 tions, 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 along the hedges as they walk : these last sounds 

 seem intended for menace and defiance. 



The grasshopper-lark chirps all night in the height of summer. 



