. The physiology of the Invertebrata. e cells of the Forifem-converts starch into glucose. It form,s an emulsion withneutral fats, and finally decomposes them into fatty acids-and glycerol (glycerine). The ferment also converts albumi-noids into peptones, which become partially converted intoleucin and tyrosin. There is no doubt that the cells ofthe Porifera secrete a ferment in every way analogous to thepancreatic ferment of higher forms. The has also obtained similar results with maB/* Archives de 2oologie Ea^irimentale, tome 7, p. 400. PHYSIOLOGY OF THE INVERTEBRATA.


. The physiology of the Invertebrata. e cells of the Forifem-converts starch into glucose. It form,s an emulsion withneutral fats, and finally decomposes them into fatty acids-and glycerol (glycerine). The ferment also converts albumi-noids into peptones, which become partially converted intoleucin and tyrosin. There is no doubt that the cells ofthe Porifera secrete a ferment in every way analogous to thepancreatic ferment of higher forms. The has also obtained similar results with maB/* Archives de 2oologie Ea^irimentale, tome 7, p. 400. PHYSIOLOGY OF THE INVERTEBRATA. 83 species of the Actiniae, only the digestive ferment secreted bythe cells of these animals does not appear to have the samedegree of activity as that extracted from the Porifera. Itsaction is much slower. The digestive apparatus of Wrasier rubens (one of theAsteridea) has been examined by the author. The walls andcontents of the wide sacculated stomach, and its five sacs donot contain digestive ferments; for the digestive fluid is. Fig. 23.—Stomach and Pyloric C^ca of Uraster. derived from the pyloric cseca situated in each ray. Thepyloric sac, or stomach, gives off five radial ducts, each ofwhich divides into two tubules (Fig. 23) bearing a number oflateral follicles, whose secretions are poured into pyloric sacand intestine.* The secretion (of the cseca) was obtained from a largenumber of star-fishes, and gave the following reactions :— * Proceedings of Boyd Society of Edinburgh, vol. 15, p. in ; and Pro-ceedings of Boyd Society of London, vol. 44, p. 325. 84 PHYSIOLOGY OF THE INVERTEBRATA. (a) The secretion forms an emulsion with oils yieldingsubsequently fatty acids and glycerol. (h) The secretion decomposes stearin, with the formationof stearic acid and glycerol— 0„H,,„0, + 3 H,0 = 3 0„H3,03 + C3H3O3. (c) The secretion acts upon starch paste with the formationof dextrose. The presence of dextrose was proved by theformation of brownish-red cuprous oxide, with


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Keywords: ., bookcentury1800, bookdecade1890, booksubjectinverte, bookyear1892