Fig. 120 illustrates another instance of the same condition in the adult. In this case the duodenum was coiled twice upon itself and adherent to the prerenal parietal peritoneum. [Illustration: FIG. 120.--Abdominal viscera of adult human male; non-rotation of intestine. (Columbia University Museum, Study Collection.)] Fig. 121, presenting the same adhesion of the duodenum, illustrates very perfectly the persistence of the narrow duodeno-colic isthmus in cases of non-rotation, as well as the development of the different segments of the adult tract from the limbs of the embryonal umbilical intestinal loop. [Illustration: FIG. 121.--Abdominal viscera of adult human male; non-rotation of intestine. (Columbia University Museum, Study Collection.)] It will be observed that beyond the duodeno-colic isthmus the coils of the jejuno-ileum have resulted from the increase in length of the descending limb, the apex and the proximal part of the ascending or recurrent limb, carrying the ileo-colic junction and caecum. The remainder of the ascending limb, terminating in the embryonic condition at the splenic flexure by passing into the descending colon, has in the course of further development in this individual produced a straight segment--the misplaced ascending colon--and a convoluted and bent representative of the normal transverse colon. The same disposition of the large intestine may be noted in the other preparations. Fig. 122 shows an instance of non-rotation observed in the human infant at two years of age. [Illustration: FIG. 122.--Abdominal viscera of child, two years old; non-rotation of intestine. (Columbia University Museum, Study Collection.)] [Illustration: FIG. 123.--Human foetus at term; abdominal viscera, hardened _in situ_; non-rotation of caecum. (Columbia University Museum, No. 1813.)]