BIGGEST AND BUSIEST FACTORY 195 



When we now examine our friend to see how his 

 breakfast has progressed, and which has now been under 

 way for six hours, we observe appearances which bewilder 

 us at first. Within an extensive area of the lower part of 

 his body, from the region of his stomach above to deep 

 within the pelvis below, we see scattered everywhere small, 

 flecked, broken-up shadows, like thin wispy clouds which 

 veil the moon. There is no hurry or scurry amongst 

 them ; their grouping changes slowly, almost impercep- 

 tibly ; here and there we may note a sudden movement ; 

 at times we notice a shadow break up or a fresh one 

 gather. But there is no drift in any decided direction. 

 The stomach, as we have already noticed, had become 

 free from all traces of bismuth two hours before. The 

 first part of the small intestine or bowel — the U-shaped 

 duodenum (see fig. 39) — we still see marked out by an 

 almost continuous band. The only other fixed shadow 

 is found in the right side of the belly between the navel 

 and the right hip-bone. Here we see the bismuth break- 

 fast accumulating in another chamber or factory — the 

 blind sac or caecum which forms the first part of the colon 

 or great bowel. With some manipulation we can make 

 out a pencil-like shadow passing from the caecal shadow 

 towards the pelvis, which tells us that bismuth-laden 

 material is entering the worm-like appendix of the caecum 



( fi g- 43)- 



We notice, too, another well-marked shadow approach- 

 ing the caecum from the pelvis — the loaded end of the 

 small bowel. The appearance gives the impression that 

 the bismuth-laden chyme finds some difficulty in obtaining 

 entrance to the caecum. So it has, for its passage is 

 guarded and regulated by anothor janitor or sphincter 

 mechanism — the ileo-caecal sphincter, so called because it 

 lies at the junction of the lower part of the small bowel 

 or ileum and the caecum (fig. 44B). It might well be 

 named the ileal sphincter, for its chief use is to regulate the 

 passage of the ileal contents from the ileum to the caecum. 

 But it does serve another purpose ; however vigorously 

 we press on the caecum we cannot press its contents into 



