THE ORIGIN AND DEVELOPMENT OF THE GAS- 

 TRIC GLANDS OF DESMOGNATHUS, AMBLY- 

 STOMA AND PIG. 



MARY J. ROSS, 



FROM THE LABORATORY OF HISTOLOGY AND EMBRYOLOGY, CORNELL UNIVER- 

 SITY, ITHACA, N. Y. 



CONTENTS. 



Introduction 66 



Technique 67 



Origin of Gastric Glands 68-93 



() Desmognathus 68-77 



(6) Amblystoma 77-&S 



(0 Pig 85-93 



General Summary 93 



Bibl iography 94 



INTRODUCTION. 



A precursory study of the glands of the pig's stomach success- 

 fully demonstrated at the very beginning of this investigation the 

 difficulties attendant upon a true understanding of the real origin 

 of the stomach glands from the study of such a complex form. 

 I am glad, here, to acknowledge my indebtedness to Dr. B. F. 

 Kingsbury, who suggested the form Amblystoma, and to Mr. 

 C. H. Boxmeyer, who suggested, and assisted me in procuring 

 the material for the study of Desmognathus. It is to the study 

 of this latter form I ascribe any success I may have had in this 

 investigation. 



Many investigators have been interested in the origin and func- 

 tion of the different cells, as parietal and central, in the glands of 

 the stomach, but few have studied the development of the glands 

 for itself alone. Thus only can one account for the lack of 

 accurate information on this subject. The present paper goes, 

 perhaps, to the opposite extreme, in being concerned solely with 

 the origin of the glands from the earliest recognizable stages, 

 until it can be clearly demonstrated that true glands are formed. 

 In Desmognatlms this has been comparatively simple, in Ainbly- 



66 



