90 NATURAL HISTORY. 



to any bigness, and in the building prove firm and 

 hard. 



Experiment solitary touching the altering of the colour 

 of hairs and feathers. 



851. Living creatures (generally) do change their 

 hair with age, turning to be grey and white : as is seen 

 in men, though some earlier, some later; in horses that 

 are dappled, and turn white ; in old squirrels that turn 

 grisly ; and many others. So do some birds ; as cyg 

 nets from grey turn white ; hawks from brown turn 

 more white. And some birds there be that upon their 

 moulting do turn colour ; as robin-red-breasts, after 

 their moulting, grow to be red again by degrees ; so 

 do goldfinches upon the head. The cause is, for that 

 moisture doth (chiefly) colour hair and feathers ; and 

 dryness turneth them grey and white : now hair in 

 age waxeth drier ; so do feathers. As for feathers, 

 after moulting, they are young feathers, and so all 

 one as the feathers of young birds. So the beard is 

 younger than the hair of the head, and doth (for the 

 most part) wax hoar later. Out of this ground a man 

 may devise the means of altering the colour of birds, 

 and the retardation of hoar hairs. But of this see in 

 the fifth experiment. 



Experiment solitary touching the differences of living 

 creatures, male and female. 



852. The difference between male and female, in 

 some creatures, is not to be discerned, otherwise than 

 in the parts of generation : as in horses and mares, 

 dogs and bitches, doves he and she, and others. But 

 some differ in magnitude, and that diversly ; for in 



