( ^3 ) 



am fully perfuaded no one will ever be able to dive into, and to ex- 

 plain their caufes and effe6ls. 



If we examine the wings of this creature by the microfcope, we 

 fhall find them covered with an incredible number of feathers, of 

 of fuch various forms, that if an hundred or more of them were to 

 be feen lying together, each would appear of a different fliape. To 

 fliew more clearly this wonderful obje6t, I caufed eight different fea- 

 thers to be delineated, for 1 do not remember that I ever favv them of 

 fo curious a make in any other flying infe6f. Thefe feathers are 

 fliewn at ;%• 34, A B C D E F G H I K L M N O, and the letters A C E G 

 ILN, denote their quills which were fixed in the membrane or fkin 

 of the wing. 



Although the microfcope by which thefe feathers were drawn, re- 

 prefented objects very diftinftly, the limner could not, through it, 

 iee the ftreaks or ribs in each feather, until I pointed them out to 

 him. Therefore I put into his hands a microfcope which magni- 

 fied objects almoft as much as that by which the Silk-worm's 

 thread was drawn, defiring him to give the figure of that feather 

 which tlirough it he could fee the mofl; diftiiKfUy. This is done at 

 fiS- 35' PQ^' ^'^ which plainly appear a great number of ftrcaks or 

 parts like ribs, which give ftrength to the feather, and in fome of 

 thefe feathers, where they fpread very wide, as at the part marked 

 R, I have counted as many as thirty of thefe fireaks, and if we con- 

 fider that every feather is nouriflied througli the quill which is pic- 

 tured at P, how many and how various mufl be the veflels in this 

 quill ? 



After this, I wiped off the feathers from a part of one of the wings, 

 that I might difcover how clofe they were placed together, and I 

 found that they were about an hair's breadth afunder. And if, as 

 a certain writer affcrts, 640 hairs breadths are equal to one inch, we 

 may demonfiratively conclude, that the four wings of this inlbftare 

 covered with more than four hundred thoufajid feathers, for the fur-- 



