1032 THE ORGANS OF DIGESTION, 



in adults to the extent of 2 per, cent. The caecum is conical, and the appendix 

 rises from its apex in line with the axis of the colon. The three longitudinal 

 bands of the colon start at the root of the foetal appendix about equidistant, and 

 pass up over the caecum and colon as described, dividing them into three rows of 

 sacculations. The second type (Fig. 652, B} has substituted the conical caecum 

 for a more quadrate one. The appendix is in the centre of two sacculi of equal 

 size instead of at the apex of a cone. There is an equal extent of intestine on 

 each side of the anterior band. The higher apes have this type e. g. gibbon. 

 In the human subject it occurs in 3 per cent. The third type (Fig. 652, (7) is 

 the normal type found in man. The walls of the caecum have grown at unequal 

 rates. The right saccule and anterior wall, probably due to better blood-supply, 

 have outstripped the left saccule and posterior wall. The appendix still rises 

 from the true apex, the three bands still start from its root, but they are all now 

 found to the left and posteriorly near the ileo-colic junction. A new or false 

 apex has appeared, which really is the exaggerated convexity of the right sac- 

 cule situated between the anterior and postero-external bands. This form occurs 

 in 90 per cent., and hence is of great surgical importance, as it simplifies the 

 location of the appendix. In the fourth type the condition of the third has gone 

 still farther. The right saccule and parts to the right of the anterior band have 

 excessive development, while the parts to the left of the band are atrophied. 

 Here the anterior band runs to the inferior angle of the ileum, while the cgecum 

 and the appendix seem to rise from the ileo-colic junction (Fig. 652, 7>). This 

 occurs in 4 or 5 per cent. 



Berry has gone over the same work and obtained nearly the same percentages, 

 proving that in about 90 cases out of 100 the base of the appendix bears a definite 

 relationship to the ileo-caecal junction. 



Sometimes the caecum is small and insignificant, may be enormous ; may be 

 rotated so the ileum passes behind and enters on the right side ; or the left parts 

 may be so developed that the ileum enters anteriorly. 



Vermiform Appendix. Starting from what was originally the apex of the 

 tube, the inner and back portion of the caecum, usually 1.7 cm. below the 

 ileo-colic opening, is a famous narrow round part of the intestine called the 

 appendix cceci, or, on account of its worm-like appearance, appendix vermi- 

 formis. This is first seen low down among the mammals, in the marsupial 

 group, in the wombat. No sign of it again appears till the ichneumon and 

 pig are reached, but not then is it a proper appendix. It is next seen in the 

 lemurs and higher apes, as chimpanzee, orang, gibbon, and gorilla. Finally in 

 man it is present as a functionless and dangerous structure. Its length, aver- 

 aged from eleven authors, is 9.2 cm. Its extremes are 1 to 9 inches, or 3.1 

 cm. to 23 cm. It attains its greatest length between the twentieth and for- 

 tieth years (Berry). Its length compared to that of the large intestine is 1 to 

 10 in the new-born, and 1 to 20 in the adult. There is no relation between 

 size of caecum and length of appendix. Its diameter is 6 mm. at base and 5 

 mm. at apex. 



The appendix has no set position. Treves considers it to pass most frequently 

 up from behind the caecum to the left behind the ileum and mesentery toward the 

 spleen. Others regard this position as nearly abnormal. Turner of Russia finds 

 it hanging into the true pelvis in 51 out of 83 cases, and transversely across the 

 promontory in 20 more of those cases. 



Berry gives order of frequency as : 1. Pelvic position ; 2. Retro-csecal ; 3. In- 

 ternal caecal (toward spleen) ; 4. Variable. 



The order of frequency found in this country by J. D. Bryant 1 was most 

 often "inward," then "behind caecum," "downward and inward," "into true 

 pelvis." 



The explanation of an up-turned or down-turned appendix is probably to be 

 sought in fcetal life. If the distal end of the appendix gain adhesions with the 



1 Ann. Surg., vol. 17, 1893, p. 164. 



