Buchanan's Journal of Man, May 1887 / Volume 1, Number 4

by Unknown

Nevertheless, in men and animals killed in full health there is very little serum in any part of the brain, the blood requiring all the space there is for fluids; and as the blood distends one part of the brain more than another in consequence of local excitement, the other portions of the brain, which are in a passive state, are compressed and deprived of their full supply of blood, so that they are of less nourished and their development declines.

Thus do we hold our destiny in our own hands. If we will cultivate the faculties which are most in need of cultivation, their organs, receiving more blood, will grow faster than any other portions of the brain, while the organs that are kept in check and deprived of activity will gradually decline in power and size, so that the character will become essentially changed. It is in the power of every individual who has the necessary determination to change essentially his own nature for better or worse, as well as to modify and enlarge his capacities, changing the structure of his brain; and this should encourage every young man and woman to make for themselves a noble destiny. Moreover, it is still more practicable to accomplish this by means of education, with all proper appliances for the young; and this should encourage philanthropists to struggle for that social regeneration which is so clearly possible for all the world, as I have shown in “The New Education.” The study of the anatomy of the brain and the innumerable experiments I have made on the brain, showing how completely the brain of the impressible can be revolutionized in its action in a few minutes, make it very apparent that society as a whole is responsible for the continued existence of criminals, paupers, and lunatics; for there should not be one, and would not be, if mankind could be aroused from their criminal apathy and ignorance to the performance of our duty in education. But alas! “the light shineth in darkness and the darkness comprehendeth it not.”

The study of the brain continually leads us into grand philanthropic conceptions by showing the splendid possibilities of humanity,—showing how near we are to a nobler social state from which we are debarred by ignorance, by moral apathy, by ignorant self sufficiency, by intolerant bigotry, and by selfish animality,—qualities which, alas! pervade all ranks to-day.

But returning from this digression to our study of the interior of the brain: the great ventricles of which we have considered the position, and which are called lateral ventricles, are interesting for another reason, that they are the central region around which the cerebrum is developed, as it folds over upon itself in its early growth, and consequently must be borne in mind as its centre when we are studying its comparative development in different heads. The basilar organs lie below the ventricles and the coronal organs above.

If we have inserted a finger under the corpus callosum, the fibres of which are above our finger, we may feel below, the structure which may be called the bottom of the ventricle, and which is likewise the base or trunk of the superincumbent parts from which they spring, as a tree from its stump.

This structure is one mass, called anteriorly the corpus striatum, or striated body, and posteriorly the optic thalamus or bed of the optic nerve, though the optic nerve has its principal origin in another part, called the optic lobes. The thalamus and corpus striatum are called together, the great inferior ganglion of the brain. They are masses of gray substance, with white fibres from below passing through them, and white fibres originating in them to ascend and spread, so that their entire masses of fibres, ascending and spreading out like a fan, constitute an extensive structure which folds together toward the median line somewhat like a nervous sac, inclosing the cavity of the ventricle and sending its representative fibres across the median line,—which are called the corpus callosum. This will be more fully explained when we consider the genesis of the brain as it grows in the unborn infant.

As the reader now understands the principal parts around the ventricles, let him look lower down to complete the survey and understand the plan of the brain, though not its anatomical minutiæ. The optic thalamus is indicated in the engraving, but the corpus striatum, being more exterior and anterior, does not appear. Practically they may be regarded as one body.

Where the thalami come together and touch or unite on the median line, the junction is called a commissure (commiss. med.) and the space between them where they do not touch is called the third ventricle (ventric. III), which, like the lateral ventricles, may also hold a little serum. It is unnecessary to consider the small parts above the thalami, the choroid plexus of blood vessels, the fornix or strip of nerve membrane, and the septum lucidum or delicate fibres under the corpus callosum.

Beginning at the bottom of the figure, we observe the medulla oblongata rising from the spinal cord to reach the cerebrum. Behind this we see the cerebellum divided on the median line, and thus presenting where it is divided the appearance called arbor vitæ, from its resemblance to the leaf of that evergreen.

As the fibres of the medulla oblongata ascend they pass between the cerebellum and the pons Varolii (bridge of Varolius) mingling with its substance. The pons or bridge (for if the brain were laid on its upper surface the pons would appear like a bridge over the river represented by the medulla oblongata) is the commissure or connecting body of the cerebellum, as the corpus callosum is of the cerebrum. When the head is held erect the fibres of the pons arch forward from the interior of the cerebellum on one side across the median line to the other side, so that a straight line through from the right to the left ear would pierce its lower portion. It looks toward the front, corresponding with the upper jaw, just below the nostrils, through which region it may be reached for experiment.