PREFACE, 
On each fide the Shafts, are the 
Vanes, broad on one fide, narrow on the other: Each vane 
confifts of a multitude of thin lamina *, fluff, and of the nature 
of a fplit quil. Thefe lamina are clofely braced together by 
the elegant contrivance of a multitude of fmall briftles ; thofe on 
one fide hooked, the other ftrait, which lock into each other, and 
keep the vanes fmooth, compadt, and ftrong. 
The vanes near the bottom of the fhafts are foft, uncon- 
nedted, and downy. 
Feathers are of three kinds ; fuch as compofe the inftru- 
ments of flight •, as the Pen-feathers ; or thofe which form 
the wings and tail, and have a large fhaft. The vanes of the 
exterior fide bending downward, of the interior upwards, lying 
clofe on each other, fo that, when fpread, not a feather mifles 
its impulfe on the airf. The component parts of thefe feathers 
are defcribed before. 
The feathers that cover the body, which may be properly 
called the Plumage, have little fliaft, and much vane, and never 
are exerted or relaxed, unlefs in anger, fright, or illnefs. 
The Down, Plum a , which is difperfed over the whole body 
amidft the plumage, is fliort, foft, unconnedted, confifts of lanu- 
ginous vanes, and is intended for excluding that air or water 
which may penetrate or efcape through the former. This is par- 
ticularly apparent in aquatic birds, and remarkably fo in the An- 
serine tribe. There are exceptions to the forms of feathers. 
The vanes of the fubaxillary feathers of the Paradise are un- 
connedted, and the lamina diftant, looking like herring-bone. 
* Durham's phyfic. theol, 336. tab. f. 18, 19. f Derham. 
c 
lx 
Vanes. 
Pen-feathers. 
Plumage. 
Down. 
Thofe 
