The authors make a histological and histochemical study of the articular capsule, in arthrosis and senescence. They basically observe fibrosis and a decrease of the elastic tissue in aged subjects and an increase in the level of acid mucopolysaccharides of the interstitial in more than 50% of arthrosics. There are also micro-deposits of amyloid substances in more than 25% of subjects over eighty. This study provides an argument in favor of the opinion of Lagier according to which arthrosis should not be considered the same as a manifestation of senescence. On the other hand, it appears that microscopic amyloidose of the articular capsule of the old patient is not related to arthrosic phenomena but rather constitutes a local manifestation of senescence.