198 
THE RUBY-THROATED HUMMING-BIRD. 
insects, similar in so far to that of the Woodpeckers, although presenting a 
different modification in its horny extremity, which is more elongated and 
less rigid. All observers who have written on the tongue of the Humming- 
birds, have represented it as composed of two cylindrical tubes, and the 
prevalent notion has been that the bird sucks the nectar of flowers by means 
of these tubes. But both ideas are incorrect. There are, it is true, two 
cylindrical tubes, but they gradually taper away toward the point, and 
instead of being pervious form two sheaths for the two terminal parts or 
shafts of the glosso-hyal portion of the tongue, which run nearly to the tip, 
while there is appended to them externally a very thin-fringed or denticu- 
late plate of horny substance. The bird obviously cannot suck, but it may 
thrust the tip of the tongue into a fluid, and by drawing it back may thus 
procure a portion. It is, however, more properly an organ for the prehen- 
sion of small insects, for which it is obviously well adapted, and being 
exsertile to a great extent enables the bird to reach at minute objects deep 
in the tubes and nectaries of flowers. That a Humming-bird may for a 
time subsist on sugar and water, or any other saccharine fluid, is probable 
enough; but it is essentially an insect-hunter, and not a honey-sucker. 
The oesophagus, fig. 2, is 1 inch 4 twelfths long, 1-J twelfths in width at 
the top, but toward the lower part of the neck enlarged to II twelfths. On 
entering the thorax, it contracts to i twelfth ; and the proventriculus is 11 
twelfths. The stomach is extremely small, of a roundish or broadly 
elliptical form, 1£ twelfths in length, and 1 twelfth in breadth. The 
proventricular glands form a complete belt, 2 twelfths in breadth. The 
walls of the stomach are moderately muscular ; the epithelium dense, with 
broad longitudinal rugae, four on one side, three on the other, and of a pale 
red colour. In the stomach were fragments of small coleopterous insects. 
The intestine is 2 inches 2 twelfths in length, from II twelfths to i twelfth 
in width. It forms six curves, the duodenum returning at the distance of 
8 twelfths. There are no coeca. The cloaca is very large and globular. 
The trachea, fig. 1, is 9 twelfths long, being thus remarkably short on 
account of its bifurcating very high on the neck, for if it were to divide at 
the usual place, or just anteriorly to the base of the heart, it would be 4i 
twelfths longer. In this respect it differs from that of all the other birds 
examined, with the exception of the Roseate Spoonbill, Platalea Ajaja, the 
trachea of which is in so far similar. The bronchi are exactly h inch in 
length. Until the bifurcation, the trachea passes along the right side, 
afterwards directly in front. There are 50 rings to the fork ; and each 
bronchus has 34 rings. The breadth of the trachea at the upper part is 
scarcely more than i twelfth, and at the lower part considerably less. It is 
much flattened, and the rings are very narrow, cartilaginous, and placed 
