the name, as descriptive of the head of these species.  This is a common fish at all seasons; but in December and January it sometimes abounds to such a degree, that, as they are not much esteemed, I have known them sold at thirty for a penny.  It keeps near the bottom commonly, at no great distance from land; but sometimes multitudes will mount together to the surface; and move along with the first dorsal fin above the water:  they will even quit their native element, and spring to the distance of a yard; thus imitating the flying gurnard, though not to the same extent.  In summer they are found basking in the sun, perhaps asleep, as they will at times display no signs of animation, until an attempt is made to seize them.

“In reference to some observations by Mr. Yarrell, in the Zoological Journal, relative to the distinction between the sprat and the young of the pilchard and herring, I can state that Cornish fishermen term the young of both the latter fishes sprats; but, how far this should go in determining the judgment of a naturalist will appear, when I add that I have never seen above one specimen of the genuine sprat in Cornwall, and that was brought me by a fisherman, to be informed what fish it was.  In taking fish out of his net by night, he felt it to be neither a pilchard nor a herring, and supposed it something rare.”

* * * * *

STRUCTURE OF BIRDS.

Birds may be said to constitute an isolated class of beings.  They are distinguished by certain characters from all other animals:  their classification does not pass into any other, and cannot, therefore, be consistently introduced into the supposed chain or gradation of natural bodies.

The skeleton or bony frame of birds is in general lighter than in quadrupeds.  They have the largest bones of all animals, in proportion to their weight; and their bones are more hollow than those of animals that do not fly:  air-vessels also enable them to blow out the hollow parts of their bodies, when they wish to make their descent slower, rise more swiftly, or float in the air.  The spine is immovable, but the neck has a greater number of bones, (never less than nine, and varying from that to twenty-four,) and consequently of joints, and more varied motion, than in quadrupeds.  The breast-bone is very large, with a prominent keel down the middle, and is formed for the attachment of very strong muscles:  the bones of the wings are analagous to those of the fore-legs in quadrupeds, but the termination is in three joints or fingers only, of which the exterior is very short.  This will be better understood by the annexed: 

[Illustration:  Skeleton of a Turkey.]