Pedagogical Anthropology

by Maria Montessori

Fig. 4.—An Egg and Spermatozoon of the same Species, about to Fertilise It. Note the difference in the proportional size of the two cells.

After the ovum-cell is fertilised, it constitutes the first cell of the new being; that is, it contains potentially a man. But as seen through the microscope, it is really not materially anything more than a microscopic cell, undifferentiated, and in all things similar to other independent cells or to fertilised ovarian cells belonging to other animals. That which it contains, namely, man, often already predetermined not only in species, but in individual characteristics—as, for instance, in degenerative inferiority—is certainly not there in material form.

At an early stage of the embryo's development, it exhibits a form analogous to that of the volvox; namely, a hollow sphere, called the morula; and subsequently, by the process of invagination, two layers of cells, an inner and an outer, are formed, together with the first body cavity, destined to become the digestive cavity, and also a pore corresponding to the mouth.

This formation has received the name of gastrula (Fig. 10, facing page ([72])), and the two layers of cells are known as the primary layers, otherwise called the ectoderm and the entoderm. To these a third intermediate layer is soon added, the mesoderm. These three layers consist of cells that are not perceptibly differentiated from one another; but potentially each and every one contains its own special final cause. In each of the three layers, invaginations take place, furrows destined to develop into the nervous system, the lungs, the liver, the various different glands, the generative organs; and during the progress of such modifications, corresponding changes take place in the elementary cells, which become differentiated into tissues. From the ectoderm are developed the nervous system and the skin tissues; from the entoderm, the digestive system with its associate glands (the liver, pancreas, etc.); from the mesoderm, the supporting tissues (bones and cartilage) and the muscles. But all these cells, even the most complex and specialised, as for example those of the cerebral cortex, the fibres of the striped muscles, the hepatic cells, etc., were originally embryonic cells—in other words, simple, undifferentiated, all starting on an equal footing. Yet every one of them had within it a predestined end that led it to occupy, as it multiplied in number, a certain appointed portion of the body, in order to perform the work, to which the profound alterations in its cellular tissues should ultimately adapt it.

Like children in the same school, these embryonic cells, all apparently just alike, contain certain dormant activities and destinies that are profoundly different. This unquestionably constitutes one of the properties of life, namely, the final cause; it is certainly associated intimately with metabolism and nutrition, considered as a means of development and not as a cause. Upon metabolism, however, depends the more or less complete attainment of the final cause of life. In man, for example, strength, health, beauty, on the one hand, degeneration on the other, stand in intimate relations with the nutrition of the embryo.[5]

The Theories of Evolution.—At the present day, there is a general popular understanding of the fundamental principles involved in the mechanical or materialistic theories of evolution which bear the names of Lamarck, Geffroy-Saint-Hilaire, and more especially the glorious name of Charles Darwin.

According to these theories, the environment is regarded as the chief cause of the evolution of organic forms. Charles Darwin, who formulated the best and most detailed theory of evolution, based it on the two principles of the variability of living organisms, and heredity, which transmits their characteristics from generation to generation. And in explanation of the underlying cause of evolution, he expounded the doctrines of the struggle for existence and the natural selection of such organic forms as succeeded to a sufficient degree in adapting themselves to their environment.

Whatever the explanation may be, the substantial fact remains of the variability of species and the successive and gradual transition from lower to higher forms. In this way, the higher animals and plants must have had as antecedents other forms of inferior species, of which they still bear more or less evident traces; and in applying these theories to the interpretation of the personalities of human degenerates, he frequently invoked the so-called principle of atavism, in order to explain the reappearance of atavistic traits that have been outgrown in the normal human being, certain anomalies of form more or less analogous to parallel forms in lower species of animals.

There are other theories of evolution less familiar than that of Darwin. Naegeli, for instance, attributes the variability of species to internal, rather than external causes—namely, to a spontaneous activity, implanted in life itself, and analogous to that which is witnessed in the development of an individual organism, from the primitive cell up to the final complete development; without, however, attributing to the progressive alterations in species that predestined final goal which heredity determines in the development of individual organisms.

The internal factor, namely life, is the primary cause of progress and the perfectionment of living creatures—while environment assumes a secondary importance, such as that of directing evolution, acting at one time as a stimulus toward certain determined directions of development; at another, permanently establishing certain useful characteristics; and still again, effacing such forms as are unfit.