Regard a man under the influence of a sublime or heroic thought, with his head proudly elevated and nostrils dilated,—he raises himself to his utmost height; while, at the idea of infinity, or the prospect of a boundless expanse, the arms are involuntarily extended as though he would soar away into unlimited space. The impress of pride is stamped in the bold erect bearing, and that of fear in the drooping head and timid step. So true is it that joy and sorrow, love and hate, pain and pleasure, virtue and vice, all betray themselves by their organic signs, that when any of these affections are habitual, or frequently recur, their external manifestations become permanently marked in the form; and it is in this sense that the habits and emotions of early youth stamp the lineaments with a character never to be effaced, or which, in _many cases_ at least, are destined to endure through life. Are we not then justified in concluding, that the kind and degree of mental developement,—the presiding thought,—the ruling and predominating principle of life, is influenced by the physical temperament and constitution, and that this latter is in its turn reacted upon by the mind? PARTICULAR PARTS OF ORGANISM INDICATIVE OF MODE OF LIFE AND MENTAL TENDENCY. We have next to inquire, whether that which is undoubtedly true with respect to the whole does not also obtain with respect to a part? whether, in fact, from the examination of a small portion of an organism—an extremity, for example—we should be enabled to determine the nature, mode of life, and mental tendency of the being to which it belonged? For a satisfactory solution of this important question we must appeal to the testimony afforded by the animal world. CHAPTER III. “Bestimmt Die Gestalt die Lebensweise des Thieres Und die Weise zu leben sie wirkt auf alle Gestalten Mächtig Zurück.”—GÖTHE, _Metamorphose der Thiere_. CORRESPONDENCE BETWEEN FORMS AND HABITS OF ANIMALS. The most simple observation renders at once apparent a correspondence between the external form of animals, the general direction of their tendencies, and their habits.