In infancy and in youth, the vital energy of the cellular texture is very conspicuous; at this age, the fleshy granulations, essentially cellular as we have seen, arise more promptly and go through their periods more rapidly than at any other age; the union of wounds is easier; and all tumours, have in their development and their progress, a rapidity that particularly depends upon the high degree to which the vital forces of the cellular system are raised at this period. It is to the same cause, that must be referred the facility of absorption of serous fluid, which sometimes infiltrates accidentally the cells, as we see in the scrotum, the eye-lids, &c.; the suddenness of the formation of cysts, &c.; then dropsies are much less frequent. When they do take place, why are the superior extremities almost as often affected as the inferior, whilst the leucophlegmasia of adults commences almost always in the last? This is then as remarkable a phenomenon, as the singular tendency that there is in the legs of being infiltrated, compared with the arms. Does not this depend upon situation, which, forcing the lymph to ascend against its weight, gradually weakens the absorbents when it has continued for some time? This explains, why varices are, as we know, more frequent in the inferior than superior extremities. II. _State of the cellular system in the after ages._ In the adult, the cellular texture is condensed and becomes firmer; its layers have a more compact texture. It appears also to lessen in quantity, because as the organs increase in thickness, their interstices are contracted. If there is not a real diminution, there is at least one in comparison with the state of the organs. It is to this circumstance that must be attributed in part, their prominence under the integuments, the striking appearance of the form of the muscles, &c. It appears besides, that the quantity of cellular texture varies according to temperaments; that in those called phlegmatic or lymphatic, it predominates over the other systems, and in the bilious, which is characterized by a dryness and rigidity of fibre, it is in the smallest proportion. In women, it is in larger quantity than in men; the roundness of their forms is in part the result of this. The motion of a part appears to have no effect in producing a more active nutrition of its cellular texture, as takes place in the muscles, the nerves, and sometimes even in the blood-vessels.