We do not see upon the external surface of the skin of the fœtus most of the wrinkles of which we have spoken above. Those of the face in particular are not seen; the kind of immobility, in which the facial muscles are, is evidently the reason of it. The forehead, the eyelids, the edges of the lips, &c. are smooth. Besides, the abundance of fat which then distends the integuments of the cheeks, prevents every species of fold there. As the hands and the feet are found in part bent at their articulations, by the attitude of the fœtus, different wrinkles are already formed about these articulations, principally on the hand, where however they appear less in proportion than afterwards. The curved, papillary lines are not very evident on the foot and the hand, even when the epidermis is removed. The internal surface of the skin is remarkable for the slight adhesion of the subjacent cellular texture, the cells of which filled with fatty particles are removed with great ease, by scraping this surface with the edge of a knife. We see then there the spaces already well formed, and as distinct in proportion as afterwards. By pursuing their dissection from within outwards, we insensibly lose sight of them towards the external surface where the skin is condensed. More blood enters the skin of the fœtus, than at any other period of life. It is easy to observe this in small animals taken alive from the womb of their mother; for in the fœtuses that are dead at birth, or born prematurely, the cause which destroys life, increasing or diminishing in the last moments the quantity of cutaneous blood, prevents us from drawing any conclusion as to the ordinary state by an inspection of them. The nerves are, as in all the other parts, more evident; but the papillæ, though sensible, as I have said, have not a proportionable increase. The animal sensibility is not in exercise in the skin of the fœtus, or at least it is very obscure there. This is owing to the absence of the causes of excitement. These are the surrounding heat, the waters of the amnios and the parietes of the womb, which can furnish materials for sensations; but as these causes are always uniform, and have no varieties, the fœtus can have but a very feeble perception, because acuteness of sensation requires change of stimuli. We know that heat long continued at the same degree becomes insensible, that a long continuance in a bath takes away almost entirely the sensation of the water, because habit is every thing as it respects sensation; nothing but what is new affects us powerfully. Is the organic sensibility of the skin in activity in the fœtus? does it preside over the alternate exhalation and absorption of the waters of the amnios? This is not the common opinion, it is not even a probable one; but this question is far from being settled in so precise a manner as many other points of physiology.