STUDIES OF THE MACROCHIRES. 
373 
of the plumage is quite different; and the 'position of the “ humeral 
tract ” in the pterylosis is different, being across the middle of 
the humerus in Swifts, and overlying the head of the bone in 
Humming-birds. 2. The mode of insertion of th e patagial muscles, 
as well as the form and character of these muscles themselves, is 
altogether different in the two groups. 3. The method of inser- 
tion of th e, pectoral muscles is essentially different. 4. Through- 
out the entire skeleton of this limb, the individual bones in Swifts 
and Humming-birds differ widely in characters of the very highest 
import, both morphologically and in the position, absence, and 
presence of parts. 
All this being so, I am firmly convinced that were the minor 
details in structure in these two wings carefully worked out 
under the lens of a good microscope, they too, of necessity, would 
also be found to be at variance. Indeed, in making my own 
dissections of the Trochili under a 2-inch objective I saw quite 
enough to fully confirm this suspicion. 
Finally, I must say, as I have already remarked in a previous 
paragraph, that heretofore too much stress has been laid upon 
the fact that both Cypseli and Trochili possess short humeri ; 
and, further, to my mind, shortness , per se, does not constitute a 
valid character, for if it did, some very remarkable forms would 
surely be grouped together ! My painstaking labours upon the 
wing-structure of Swifts and Humming-birds convince me fully 
that, in so far as this part of their organization is concerned, 
there is little or no affinitv at all. 
0 * 
Notes on the Anatomy of the Pelvic Limb in certain 
Cypseli and Trochili. 
Having shown how innately different the wing-structure in 
Swifts aucl Humming-birds really is, let us now take a look at 
their pelvic limbs. 
It will not be necessary to pass the external characters of these 
parts in review, as they are already well known ; it will be suf- 
ficient to remark that the pelvic limb of such a bird as Micropus 
differs from the pelvic limb of a Trochihis in all its more essential 
external characters. 
My investigations tend to confirm the statement of Pro- 
fessor Glarrod, that Humming-birds and the American Swifts 
Clicetura pelayica and Micropus lack the accessory femoro- 
