Step by step our lessons have made us familiar, in some degree, with the build of the human body, and, through it, with the general structure of the various members of the brute creation. We are now in a position to carry our investigations a little farther, taking still the human body as the type, and following up, as we meet with them, the various adaptations of it to suit the requirements of eachanimal. Let us commence with the head, which, as you know, consists of two distinct parts-the skull and the face.
The skull or cranium is formed of eight plates of bone, firmly joined together at their edges, so as to make an oval box to lodge and protect the brain. There is a round hole in the base of this bony box, through which the spinal cord passes into the canal provided for it, and on either side of this aperture is a smooth bony projection, by which the skull rocks on the topmost vertebra of the spinal column. These projections are termed condyles.
Turning next to the face, we find that it consists of no less than fourteen distinct bones, all of them, except one-the lower jaw-firmly and immovably fixed to each other and the bones of the skull. These fourteen bones provide five large cavities for lodging and protecting thesense organs of sight, smell, and taste.
So far, the structure of man and of all mammals is on similar lines. But man stands immeasurably above any of these creatures. "Endowed with an intellect capable of indefinite improvement, he exhibits but little of that instinct which guides the operations of the lower animals. His knowledge is the result of observation, and is matured by thought; his power of speech and the capability of writing are faculties entirely his own, whereby he can communicate his ideas and transmit to posterity the results of his experience. By no means highly gifted asrelates to his bodily strength, his swiftness is very far inferior to that of most animals of his size. Possessing neither strength of jaw nor canine fangs, he is destitute of offensive weapons, and his body being not even clothed with hair, few creatures are, in this respect, left so utterly defenseless, nay, in addition to these disadvantages, he is, of all animals, the longest in acquiring even that strength which is necessary for the supply of his simplest wants, and yet this very feebleness is to him an advantage, compelling him to have recourse to that intelligence with which he has been so highly endowed. Absolutely dependent upon parental care for his support, he must necessarily derive from that source the education of his intellect, as well as of his physical powers, and hence is established an attachment as durable as it is sacred. The very length of his pupilage necessarily gives birth to habits of family subordination, which ultimately lay the foundation of all social order, and tend to multiply indefinitely the advantages derivable from that mutual co-operation, whereby he has succeeded in subjecting orin repelling the attacks of inferior animals-in clothinghimself so as to defy the inclemencies even of the most rigorous climate, and in spreading his race over the surface of the earth.
"Nevertheless, in reviewing the grand scene of nature, the supremacy of the human race seems to be manifested in nothing more strikingly than in the privilege conferredupon mankind of studying the Creator"s works, and learning the great lessons they are so well calculated to teach.
