970 



THE ORdAXS OF DIGESTION 



beiiinniiiif than at the rml. It varies in width at different parts from two and a 

 half to one and a quarter inehes. The length from the root of the a})pendix or 

 tip of the eteeum to the point where the meso-reetum ends is, in the male, about 

 four feet eight inches, and in the female about four feet six inches. 



The extremes found in a number of cases, were for both sexes respectively, six 

 feet six inches, and three feet three inches. 



The large intestine, in all parts except the rectum, has a peculiar arrangement 

 of its walls, which gives it a very different appearance from the small intestine. 

 It is mcculdted, and the sacculation is produced by the gut having to adopt its 

 length to three shorter muscular bands which run the course of the intestine. 

 These bands, which are about 12 mm. wide and 1 nnii. thick, are really the longi- 

 tudinal tibres of the muscular wall, which are chiefly collected at three parts (fig. 

 575). One band is situated podcriorhj on the attached border, another runs onte- 

 riorly, and the third is situated on the inner side of the ascending and descending 

 colon, and on the lower border of the transverse colon. All these bands start at 

 the vermiform appendix, and are lost on the rectum. Along the Avhole length of 

 the large intestine, except the lower part of the rectum, are certain small append- 

 ages (appendices epiploicas), seen mostly along the line of the inner muscular band. 

 They are ])ouches of peritoneum containing fat. 



The caecum, or caput coli. — The caecum is a cul-de-S(tc forming the first part 

 of the large intestine. It is defined as that part of the colon which is situated 



Fig. 575.— The Four Types of C^cum. (Treves.) 

 ABC D 



below the entrance of the ileum. Its breadth is about three inches, and its length 

 about two and a half inches. 



It lies in the right iliac fossa, and is usually situated upon the psoas muscle, 

 and so ]>laced that its apex or lowest ]ioint is just projecting lieyond the inner 

 border of that inner muscle (figs. 565, 577). It is entirely enveloped in perito- 

 neum, and is free in the abdon)inal cavity. The apex of the caecum usuallv cor- 

 responds with a point a little to the inner side of the middle of Poupart's ligament. 

 Less frequently the ctecum will be found to be in relation with the iliacus musch^ 

 only; or the bulk of the caput will lie upon that nmscle, while the apex rests u]»on 

 the psoas. In a number of cases the caecum is entirely clear of both psoas and 

 iliacus muscles, and hangs over the pelvic brim, or is lodged entirely Avithin the 

 jielvic cavity. Some part of the ca)cum may pass even to the left of the median 

 line of the body. 



This part of the colon is liable to consideral)le variation. 



Its rnriation.<i may be described under Jmir typef< : 



1. The foetal type is conical in shape, the appendix arising from the apex. 

 This process is a continuation of the long axis of the colon. Th(i three mustular 

 bands Avhich meet at the appendix are nearly at equal distances apart (fig. 575, A.). 



2. The second form is more fiuadrilateral in shape than the last; the three bands 

 retain their relative positions; the appendix ap)>ears l)etwcen two bulging sacculi. 

 instead of at the summit of a cone (fig. 575, B. ). 



8. In the third tyjie. that part of the caput eoli that lies to the right side of the 



