CONTRACTION OF THE GALLBLADDER IN THE COMMON BULLHEAD (AMEIURUS NEBULOSIS)

Abstract

It is now generally accepted by almost all who study the physiology of the gallbladder that it empties through the cystic duct. Furthermore, the conviction that it is emptied by the contraction of an intrinsic musculature is becoming more and more assured. Recent observations on the gallbladder of man (Levine¹), as well as the observations of Ivy and Oldberg² on the effect of secretion on the gallbladder, further substantiate the conclusions of many others that the wall of the vesicle does contract and thereby expels bile into the cystic and common duct. As would be expected, most of the recorded observations on the emptying of the gallbladder have been made on common laboratory mammals, such as the dog, cat, rabbit and guinea-pig, because of their accessibility and because of their higher phylogenetic position with an anatomic organization more closely allied to that of man. Relatively few observations have