Note 51 — PART I.—MORPHOLOGY AND PHYSIOLOGY (continued 8)

Plateau (1877) states that the digestive fluid of insects, as well as of Arachnids, Crustaceans, and Myriopods, has no analogy with the gastric juice of vertebrates; it rather resembles the pancreatic sugar of the higher animals. The acidity quite often observed is only very accessory in character, and not the sign of a physiological property. “Farther, I have found it in insects; Hoppe-Seyler has demonstrated in the Crustacea, and I have proved in the spiders, that the ferment causing the digestion of albuminoids is evidently quite different from the gastric pepsine of vertebrates; the addition of very feeble quantities of chlorhydric acid, far from promoting its action, retards or completely arrests it.” (Bull. Acad. roy. Belgique, 1877, p. 27.)