Oftentimes the fat accumulates in very great quantity in the cellular texture. I will not cite examples of those enormous collections, of which different authors have given a number of cases; this would be superfluous. I shall only observe, that this state of great corpulency, far from being a sign of health, indicates almost always a weakness of the absorbents which are destined to take off the fat, and has, in this point of view, much greater analogy to serous infiltrations than we commonly think. Different facts establish this assertion. 1st. Every kind of unnatural corpulency is accompanied with a debility of the muscular power, with a state of lassitude and languor of the individual who is the subject of it. 2d. In a man in whom strength and activity predominate, we do not see this fatty enlargement that hides the prominences of the muscles; these are distinctly marked. It is necessary to distinguish carefully the size of the body which arises from cellular fat, from that which is the consequence of the proper development and nutrition of the organs. 3d. Oftentimes the causes which evidently weaken the powers of life, produce a considerable quantity of fat; such as inactivity, rest, great and long continued hemorrhage, convalescence from certain acute diseases, in which the powers still languish, though fat abounds. 4th. A fatty state of the muscles is a state of evident weakness in them. 5th. I have been sometimes convinced, in examining atrophous limbs, that the small size which they retain is owing in part to the fat, which is in proportion almost equal to that of sound limbs, whilst all the other parts, the muscles in particular, are contracted and hardened. 6th. Castration, which takes from the vital powers a part of their activity, from nutrition a part of its energy, is very often marked by excessive corpulency. 7th. On the other hand, as a certain degree of development of the vital powers is necessary for generation, individuals who are too fat, in whom this degree is wanting, are in general not fitted for this function. In woman, this fact is remarkable, it is not less so in man. In other animals we make the same observation. As fowls are fattened for the table, they cease to lay eggs. Most domestic animals are governed by the same law. We should say that there is a constant relation between the secretion of semen and the exhalation of fat, and that these two fluids are in an inverse ratio to each other.