56 DIRECTIONS rOR MEASUREMENT. 



As this measurement cannot be got at all from dried skins, I do not often 

 use it in this book. But it is higlily important, and for the very reason that 

 it cannot be got afterwards, always note it doion from fresh sjDecimens. The 

 first measurement, likewise, can only be got at approximately in skins, and 

 the following details are really our chief data in all cases : — 



§ 99. "Length of wing." Distance from the angle formed at the 

 (carpus) bend of the wing, to the end of the longest primary. Get it with 

 compasses for small birds. In birds with a convex wing, do not lay the tape 

 line over the curve, but under the wing, stretching in a straight line from 

 the carpal angle, to end of longest primary. This measurement is the one 

 called, for short, "the wing;" thus when I say, simply, "^^g- 12," I mean 

 that this distance is twelve inches ; so, also, "vfg. =J tl.," means that this 

 distance is half as great as the length of the tail. 



§ 100. "Length of tail." Distance from the roots of the rectrices, 

 to the end of the longest one, whichever one that may be. Feel for the 

 pope's nose; in either a fresh or dried specimen, there is more or less of a 

 palpable lump into which the tail feathers stick. Guess as near as you can 

 to the middle of this lump ; place the end of the ruler opposite the point, 

 and see how much the tip of the longest tail feather points to. "Depth of 

 fork" and "amount of gradation," in a tail, is the difl'crence between the 

 shortest and the longest tail feathers ; in the one case the outer, iu the other 

 the middle, pair of rectrices is the longest. 



§ 101. "Length of bill." Exactly what this is, depends upon the 

 writer. Some take the curve of the upper mandible ; others the side of 

 the upper mandible from the feathers ; others the gape, etc. I take the 

 chord of the cidmen. Place one foot of the dividers on the culmeu just 

 where the feathers end — no matter whether the culmen runs u\y on the 

 forehead, or the froDtal feathers run out on the culmen, and no matter 

 whether the culmen is straight or curved. Then with me the length of the 

 bill is the shortest distance from the point just indicated to the tip of the 

 upper mandible. Measure it with the dividers. In a straight bill, of 

 course it is the length of the culmen itself; in a curved bill, however, it is 

 quite another thing. The "depth of bill" is determined opposite the same 

 point ; it is a pei'pendicular transverse dimension : the " width of the bill " is 

 determined at the same point ; it is the horizontal transverse dimension. 

 "The gape" is the shoi'test distance between the commissure proper (see 

 § 53, and fig. 5, h) and the tip of the upper mandible. 



§ 102. "Length of tarsus." This is the most important measurement 

 for the purposes of this volume. Measure it cdioays with dividers, and in 

 front of the leg. It is the distance between the joint of the tarsus with the 

 leg above, and that with the first phalanx of the middle toe below. Place 

 one foot of the dividers exactly upon the middle of the tibio-tarsal joint in 

 front. The front of this joint is rounded on either side by two little semi- 

 circular rims, or lateral elevations, more or less evident in different birds ; 

 you want to get just between them. In the softer-legged wading, or water 



