AUTHORS ABSTEACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, NOVEMBER 15 



THE EARLY ESTABLISHMENT OF THE INTESTINAL 

 NUTRITION IN THE OPOSSUM— THE DIGESTIVE 

 SYSTEM JUST BEFORE AND SOON AFTER BIRTH 



CHESTER H. HEUSER 



The Wistar Instilide of Anatomy and the Johns Hopkins Medical School 



SIX PLATES (twenty FIGURES) 



As the intra-uterine period in the opossum is very brief, the 

 intestinal nutrition commences in the newborn animals while 

 they are yet relatively very immature. Ten days after the begin- 

 ning of segmentation, or thirteen days after insemination, the 

 young opossums appear in the pouch; they become at once 

 attached to the teats, and milk soon enters their stomachs. 

 Five days before birth, however, the digestive tract of the opos- 

 sum is no further advanced than this system in the three-day 

 chick embryo; the foregut extends forward from the broad con- 

 nection with the yolk-sac, and the first rudiments of the liver, 

 hindgut, and allantois are just appearing. The transformation 

 brought about during these last five days is remarkable in its 

 rapidity. 



The stages especially considered in this report are those of the 

 embryo a few hours before birth and the pouch-young about three 

 days old. The external form of the viscera is first examined and 

 the histological structure is then studied. The stomach, small 

 intestine, and large intestine are dealt with in order, special 

 attention being given to the small intestine. 



METHODS 



This study was commenced and the material used was obtained 

 while I was a member of the staff of The Wistar Institute. The 

 specimens were collected at Austin, Texas, in cooperation with 

 Dr. Carl G. Hartman, of the University of Texas. Doctor 



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