56 DIRECTIONS FOR MEASUREMENT. 
As this measurement cannot be got at all from dried skins, I do not often 
use it in this book. But it is highly important, and for the very reason that 
it cannot be got afterwards, always note it down from fresh specimens. 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. “LenerH oF winc.” 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, “wg. 12,” I mean 
that this distance is twelve inches; so, also, “wg. =# tl.,” means that this 
distance is half as great as the length of the tail. 
§ 100. “Lenerxn or rar.” 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 difference between the 
shortest and the longest tail feathers ; in the one case the outer, in the other 
the middle, pair of rectrices is the longest. 
§ 101. “Leneru or pity.” 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 culmen. Place one foot of the dividers on the culmen just 
where the feathers end—no matter whether the culmen runs up on the 
forehead, or the frontal 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 perpendicular transverse dimension : the “ width of the bill” is 
determined at the same point; it is the horizontal transverse dimension. 
“The gape” is the shortest distance between the commissure proper (see 
§ 53, and fig. 5, 2) and the tip of the upper mandible. 
§ 102. “Leneru or tarsus.” This is the most important measurement 
for the purposes of this volume. Measure it always 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 
