STUDIES ON THE PANCREAS OF THE GUINEA PIG 



R. R. BENS LEY 

 From the Hull Anatomical Laboratory, University of Chicago 



FIFTEEN FIGURES 



CONTENTS 



Introduction 298 



Technique 302 



1. Methods for the demonstration of all the islets of the pancreas, per- 



mitting enumeration 302 



a. The neutral red method 302 



b. The janus green method 304 



2. Vital staining methods for demonstrating the ducts and their relation 



to islets and acini 305 



a. Pyronin method for demonstrating the ducts 305 



b. The methylene blue method for the demonstration of the 

 ducts 305 



3. Combination of vascular injection and vital staining for determining 



the relation of the vascular system to the islets 306 



4. Methods of fixation 307 



a. Lane's methods for demonstration of the A cells of the islets 



of Langerhans 307 



b. Lane's methods for demonstration of the B cells of the islets 



of Langerhans 307 



c. Formaline bichromate sublimate method 308 



d. Acetic osmic bichromate method 308 



5. Staining methods 308 



a. The neutral gentian method 308 



b. The safranin-acid violet method 309 



c. The acid fuchsin methyl green method 309 



d. The acid fuchsin toluidin blue method 310 



e. The neutral gentian, acid fuchsin, picric acid method 310 



f. The copper, chrome haematoxylin method 310 



The number of islets of Langerhans in the pancreas of the guinea pig 311 



The effect of certain experimental methods on the numbers of the islets of 



Langerhans in the pancreas 321 



1. Effect of secretin stimulation on the number of islets of Langerhans 



in the pancreas of the guinea pig 325 



2. Effect of secretin stimulation on the pancreas of the toad 330 



3. Effect of inanition on the number of islets of Langerhans in the pancreas 



of the guinea pig 334 



THE AMERICAN JOURNAL OF ANATOMT, VOL. 12, NO. 3 



297 



