195 THE RUBY-THROATED HUMMING-BIRD. 



purple, spotted with black, varying to crimson, orange, and deep black. 

 Sides of the same colour as the back; the rest of the under parts greyish- 

 white, mixed with green. 



Length 3^ inches, extent of wings 4|; bill along the ridge f , along the 

 gap |-; tarsus £, toe 4. 



Adult Female. 



The female differs from the male in wanting the brilliant patch on the 

 throat, which is white, as are the under parts generally, and in having the 

 three lateral tail-feathers tipped with the same colour. 



Dimensions the same. 



Young Bird. 



The young birds have the under parts brownish-white, the tail tipped 

 with white, and are somewhat lighter in their upper parts. In autumn the 

 young males begin to acquire the red feathers of the throat. 



On depriving a specimen of this bird of its feathers, one finds its 

 proportions very different from what he may have previously imagined. 

 Thus, the body is remarkably robust, of an ovate form, much deeper than 

 broad, on account of the extreme size of the crest or keel of the sternum, 

 which is so extended as to leave for the abdomen a space not more than a 

 fifth of its own length. The feet, although very small, are yet proportionally 

 as large as those of a Cormorant; the femur and tibia being relatively large, 

 while the tarsus is extremly short, and the toes of moderate size, the anterior 

 incapable of being widely spread, and the middle or third scarcely exceeding 

 the two lateral; in which respect the foot has some resemblance to that of 

 the Swifts. The hind toe is articulated remarkably high on the tarsus, it 

 being placed very nearly at the height of one-third of its length. The bones 

 of the wings are very short; the humerus and cubitus extremely so, although 

 proportionally strong. The neck is very elongated, being 10 twelfths of an 

 inch in length, whereas the body, including the coccyx, is only 9 twelfths. 

 The head is rather large, depressed in front, with a deep hollow between the 

 eyes, which are very large, and the bill is disproportionately elongated. 

 The pectoral muscles are of extreme size, exceeding by much the entire bulk 

 of the rest of the body with the neck and head, the height of the crest of the 

 sternum being 4 twelfths, or nearly half the length of the body. The body 

 of the sternum is remarkably flat, and so thin as to be almost perfectly 

 transparent; it is narrow anteriorly, where it is 2i twelfths in breadth, but 

 gradually enlarges to 4 twelfths; the posterior edge forms a semicircle, and is 

 destitute of notch. The pubic bones almost meet in front, where they are 

 cartilaginous. The heart is extraordinarily large, occupying half the length 

 of the cavity of the body, of an elongated conical form, 3| twelfths long, and 



