16 



EVENINGS AT THE MICKOSCOPE. 



of a quill when we mate a pen, is the medullary portion, 

 dried. There is a beautiful contrivance in the barbs of 

 most feathers, which I will illustrate by this feather 

 from the body-plumage of the domestic fowl. Every 

 one must have observed the regular arrangement of the 

 vane of a feather, and the exquisite manner in which 

 the beards of which it is com- 

 posed are connected together. 

 This is specially observable in 

 the wing-feathers, — a goose-quill, 

 for example ; where the vane, 

 though very light and thin, forms 

 an exceedingly firm resisting 

 medium, the individual beards 

 maintaining their union with 



great tenacity, and 



resuming it 

 have 



BAUD OF CLOTHING-FEATHEE 

 OF FOWL. 



immediately, when they 

 been violently separated. 



N'ow this property is of high 

 importance in the economy of 

 the bird. It is essential that 

 with great lightness and buoy- 

 ancy — for the bird is a flying 

 creature — there be power to strike the air with a broad 

 resisting surface. Tlie wide vanes of the quill-feathers 

 afford these two requisites, strength and lightness ; the 

 latter depending on the material employed, which is 

 very cellular, and the former on the mode in which the 

 individual barbs, set edgewise to the direction of the 

 stroke, take a firm hold on each other. 



Now, in the body-feather which is under the micro- 

 scope, we see that the central stem carries on each side 

 a row of barbs, which interlock with each other. The 



