Flowers
Dog
Dog
The Human brain
The engraving represents not an actual dissection, but the plan of the fibres as understood by the anatomist. The intricacy of the cerebral structure is so great that it would require a vast number of skilful dissections and engravings to make a correct portrait. Fortunately, this is not necessary for the general reader, who requires only to understand the position of the organs in the head, and the direction of their growth, which is in all cases directly outward from the central region or ventricles, so as to cause a prominence of the cranium—not a “bump,” but a general fulness of contour. Bumps belong to the growth of bone—not that of the brain.
The human brain
If the reader has not fully mastered the intricacy of the brain structure, he will find his difficulties removed by studying two more skilful dissections. The following engraving presents the appearances when we cut through the middle of the brain horizontally and reveal the bottom of the ventricles, in which we see the great ganglion, or optic thalamus and corpus striatum, and the three localities at which the hemispheres are connected by fibres on the median line, called anterior, middle, and posterior commissures. These commissures are of no importance in our study; they assist the corpus callosum in maintaining a close connection between the right and left hemispheres.
Newborn Cicada
Although Cicadas abound most upon the oaks, yet there seem to be no trees or shrubs that are exempt from their attacks, unless it be the various species of pines and firs. The punctured limbs languish and die soon after the eggs are laid, and as often happens are broken off by the winds; but when this is the case the eggs never hatch, for the moisture of the living branch seems necessary for their proper development. The eggs are one-twelfth of an inch in length, and one-sixteenth of an inch through the middle, but taper to an obtuse point at each end. They are of a pearl-white color. The shell is so thin and delicate that the form of the inclosed insect can be seen before the egg is hatched. One writer claims that fifty-two days, and others that fourteen days, constitute the period required for the hatching of the egg. When it bursts the shell the young insect is one-sixteenth of an inch long, and is of a yellowish-white color, excepting the eyes and the claws of the fore-legs, which are reddish. It is clothed with small hairs. In form it is grub-like, larger proportionally than the parent, and provided with six legs, the first pair being very large, shaped like lobster-claws, and armed beneath with strong spines. Little prominences take the place of wings, and under the breast is a long beak for suction. Its movements, after leaving the egg, are very lively, and nearly as quick as some of the ants.