STEM BROMELAIN, an enzyme mixture, consisting primarily of plant proteases, with limited amounts of phosphatases, and amylase (Heinicke and Gortner1) was assayed for its action on the mucopolysaccharides, mucoproteins, and collagen of steer hide. Mucopolysaccharides and mucoproteins are found in ground substance, basement membrane, sheaths and layers of the hair follicle. Collagen is found mainly in fibrous elements of hide.