This memoir details a continuation of the author's investigations on the physiology of the Invertebrata. At this point we consider the physiological functions of the so-called “liver ” of the Brachyura.

Was it not M. Letourneau, in his La Biologie, who said, “Does the pancreas exist in the invertebrates? This is a question of comparative physiology which still waits for a reply. We have seen that we do not begin clearly to recognise the pancreas except in fishes, and then only in a rudimentary state.” From the recent researches of Krukenberg, Frederieq, Jousset de Bellesme, Plateau, Hoppe-Seyler, as well as those of the author, the problem now requiring solution is the following:-Does a true liver exist in the Invertebrata? The pancreas appears to be the chief digestive organ (other than a true stomach) of the earlier forms of animal life.