1892.] Zoology. 869 
the development of its scales into feathers, the difficulty of its first 
origin is overcome and the presence of the alar membranes is explained. 
Ridgway on the Anatomy of Humming-birds and 
Swifts.—Ornithological literature has very recently been enriched 
by a monograph upon the Humming-birds, from the pen of Mr. Robt. 
Ridgway of the U. S. National Museum. It comes to me in the form 
of a reprint from the Report of that institution for 1890, and is now 
just issued. As valuable as may be the descriptive part of the contri- 
bution, I find it impossible for me to overlook certain very glaring 
errors our author has fallen into, in regard to the anatomy of the 
birds he treats. Ridgway still adheres to that now well-nigh 
exploded notion that the Humming-birds are more or less closely 
related to the Swifts, and he says “The Humming-birds and Swifts 
further agree in numerous anatomical characters, and there can be no 
doubt that they are more closely related to each other than are either 
to any other group of birds.” In setting forth some of the anatomical 
characters he claims to find in the Humming-birds, in support of this 
theory, he remarks in regards to the structure of the tongue that “it 
is hollow and divided at the tip into two slender branches * * * a. 
Now the tongue in the Humming-birds is not hollow, and I would 
kindly invite Mr. Ridgway’s attention to the very careful dissections 
of that organ made by the Scotch anatomist W. MacGillivray, and 
published in the 4th volume of Audubon’s Birds of America, and also 
the results of my own extensive dissections which appeared in Forest 
and Stream, July 14, 1887 (p. 581). 
Again our author states that “except in the shape of the bill and 
structure of the bones of the face, the Humming-birds and Swifts 
present no definite differences of osteological structure.” (p~ 290). 
This statement is not only not true, but as wide of the mark as it well 
can be, and the wonder to me is, how such a cautious and candid 
writer as Mr. Ridgway has always proved himself to be, could have 
allowed his pen to record such an error. As a matter of fact, when 
go shown, the skull 
and associate skeletal parts of a Swift depart not very markedly from 
the corresponding structures in a Swallow, while they very decidedly 
differ from the same parts as we find them in a humming-bird. ~~ 
differences are to be seen in nearly all the rest of the skeleton, when 
