specific irritability, these ganglions and these nerves must necessarily have their interior structure and their functions, differing from each other.

It is probable, that in animals, even of the lowest order, this nervous system is endowed with sensibility; but in man, and the higher animals, it is, like the spinal marrow and the nerves of the senses, entirely under the dominion of the brain. In a state of health, the viscera and the vessels execute their functions without any volition on our part, and without our having the slightest consciousness of the fact: the intestines are in fact in continual motion; they choose the nutriment which suits them, and reject heterogeneous substances; they form the secretions and the excretions.

But, we have seen that vegetables present to us similar phenomena: the capacity of being stimulated, of reacting against stimulus, a character of irritability, ought not to be confounded, as most physiologists do confound it, with the faculty of perceiving a stimulus, of having a consciousness of it, of feeling it. The perception, the consciousness of an irritation, of an impression, are inseparable from the nerve of sensation. Sensation, or organic sensibility without consciousness, is a contradiction in terms, but a contradiction very sagely preserved and professed in our schools. Sensibility, or the faculty of feeling, constitutes the essential character of the animal. When the changes produced by an impression take place without consciousness, they must be considered the result of irritability, and as belonging to automatic life; but when changes take place with consciousness, with perception, with sensation, this act of consciousness, of perceiving, belongs to the animal life.

"But," you will say, "admitting that, in a state of perfect health, we have no consciousness of what passes in the heart, stomach, liver, &c., still we feel hunger and thirst, and the need of certain evacuations; we experience trouble, uneasiness, and pains, in the intestines, &c., and in general it would be difficult to find a part of the body, the bones, tendons, and even hair, not except

ed, which may not, under certain circumstances, transmit sensations, and consequently become an organ of animal life. How happens this?"

We have seen, that the ganglions and nerves of the viscera and vessels, communicate together; they send several filaments of communication to the spinal marrow, and this is immediately connected with the brain. It is thus that all the impressions on the other nervous systems are transmitted to the centre of all sensibility, and that the influence of all the nerves on the brain, and of the brain on all the nerves, is established. It is for this reason, that the nervous apparatus of the chest and abdomen has received the name of sympathetic nerve, or, because its branches of communication take their course between the ribs to the spinal marrow, the intercostal nerve. Besides these means of reciprocal action and reaction, several nerves of the spinal marrow and of the head, such as the hypoglossal nerve, the glosso-pharyngeal, the abductor, the facial nerve, unite themselves with the sympathetic.

The organs of both lives can only perform their special functions in proportion to their development, to their organic function. Before the liver, the kidneys, the stomach are formed, there can be no secretion of bile, of urine, of gastric juice; in like manner, the propensities and talents cannot unfold themselves until the brain is developed.

The divers ganglions, plexuses and nerves of the sympathetic are not developed simultaneously; and for this reason, the functions of the organs of vegetable life do not commence and terminate simultaneously. It is the same with the various ganglions and pairs of nerves of the spinal marrow and of the nerves of the senses. Their successive aud independent development and death, explain the successive and independent perfection and failure of the various organs of voluntary motion, and of the senses.

I shall hereafter prove, that the different constituent parts of the brain, each of which is destined to a peculiar

function, are equally subjected to successive development and destruction. This explains how instincts, propensities, and talents do not all either appear or fail, at the same periods of life.

As the brain will be the subject of my meditations in all the volumes of this work, I leave it now, to answer a question of high importance, viz. Does the fetus and infant, while inclosed in its mother's womb, enjoy animal life, or, a life purely automatic? How ought its destruction to be judged of before the tribunal of sound physiology? Those who maintain that animal life is nothing but a life of relation, an external life, that all our moral qualities and intellectual faculties are the result of impressions on the senses, must necessarily maintain that the fetus and the newly-born infant are still only automata, whose destruction has no relation to an animated being.

Prochaska says, * "In the fetus and the new-born infant, the muscles have the automatic movement, and not the voluntary, because the brain is not yet in a state to think."

Bichat likewise says, † "We may conclude with confidence, that in the fetus the animal life is nothing; that all the acts attached to this age, are dependent on the organization. The fetus has, so to speak, nothing in its phenomena, of what especially characterizes an animal ; its existence is the same as that of vegetables. In the cruel alternative of sacrificing the child, or of exposing the mother to almost certain death, the choice cannot be doubtful. The destruction is that of a living

being, not of an animated being."

Yes, doubtless, it is cruel to sacrifice an unfortunate mother to a feeble fetus, still menaced with dangers without number, and on whose life it is still so difficult to calculate. Nothing but certain religious notions, or the

* Opera Minora, L. II. p. 190. + Sur la vie, et la mort, p. 125.

reasons of an ambitious policy, could ever recommend the dire counsel of immolating the mother in the most touching moment of her life, to the precarious existence of the infant. Still, as the expressions of Bichat, "the act involves the destruction of a living being, and not of an animate being," might lead to unlawful abuses, I consider it my duty as a physiologist, to rectify the arguments of Bichat and Prochaska.

I have said that neither the organic, nor the animal life, developed itself fully at once, or enjoyed simultaneously all its activity. If the possession of organic life by the fetus, were contested, because several of the functions of the viscera have not yet manifested themselves, the conclusion would doubtless be severely criticised. Is it, then, more reasonable to refuse to the fetus or to the new-born infant, the possession of animal life, because his brain is not yet formed for all its propensities, all its talents, and for the faculty of thinking? If physiologists had sooner known the plurality of the cerebral organs, and of their functions; if they had distinguished the different degrees of consciousness and sensation, the desires and necessities, from thought or reflection, they would have been cautious about affirming, that there exists no animal life in the fetus or new-born child. The brain of these beings is not, indeed, sufficiently developed to possess ideas, to combine and compare them; but, if this degree of perfection were necessary in order to allow them sensation and desires, it would be very difficult to determine at what period animal life does commence, and when the destruction of an infant becomes an act committed on an animate being, and, consequently, criminal. The infant has not yet the faculties of reflection and imagination; he feels as yet no affection for those of a different sex; he is not yet ambitious, &c., but can we refuse to him the faculty of perceiving, that of memory, of inclinations, of aversions, of joy and sorrow? If the noblest functions of the brain require a certain development and a certain consistence, who shall determine the degree of development, and of con

sistence, necessary for functions of an inferior order? The new-born child manifests by the outline of his figure, by his movements, and his cries, the states of happiness and of suffering; he equally manifests, too, the desire of nursing, and so of other sensations.

At all events, this work will become an incontrovertible proof, that there exists within us a far more fruitful source of sensations than impressions made on the senses; and consequently that it is altogether false, to assert that animal life commences only with the action of the external senses.

These considerations are sufficient to prove, that the laws of animal organization by no means support the dangerous principle, avowed by certain physiologists.

Of the Special Functions of the Brain, or those which belong to Animal Life in Man and Animals.

In the natural order of the gradation of animals, the nervous system, which presides over the voluntary movements, comes after the great sympathetic nerve. It consists of the spinal marrow inclosed in the vertebral column. And from it, to the right and left, before and behind, issue as many pairs of nerves as there are vertebræ of which the column is composed. In caterpillars, &c., the ganglions and the pairs of nerves proceeding from them, correspond in number to the segments of which the animal consists.

All these pairs of nerves go to the muscles, and give them the faculty of exercising motion.

But all these nerves, at least in the more perfect animals, must be considered rather as conductors of the cerebral influence, than as independent agents; their function ceases, as soon as their free communication with the brain is interrupted.

As, in a healthy state, these functions are exercised with consciousness, they are held to make part of animal life.