VERMIFORM PROCESS 271 



trate the muscularis mucosae. In the adult (Fig. 267) they are simple 

 tubes, occasionally forked, thus indicating the way in which they multiply 

 in the embryo. As early as the fourth month, lymphoid tissue has been 

 found in the vermiform process, and at birth the lymphoid nodules in the 

 tunica propria are abundant and more or less confluent. The great devel- 

 opment of lymphoid tissue is the most important histological feature of 

 the vermiform process in the adult (Fig. 267). It may invade and partly 



FIG. 267. TRANSVERSE SECTION OF THE HUMAN VERMIFORM PROCESS. X 20. (Sobotta.) 



Note the absence of villi and the abundance of nodules. Clear spaces in the submucosa are fat cells. Only 



a part of the circular layer of the muscularis has been drawn. 



break up the muscularis mucosae, and extend into the submucosa. The 

 latter, together with the inner circular and outer longitudinal muscle 

 layers, and the serosa, are similar to the corresponding layers of the small 

 intestine, already described. 



During the fifth month of embryonic life, Stohr has found an interesting normal 

 form of degeneration in the glands of the vermiform process (Arch. f. mikr. Anat., 1898 

 vol. 51, pp. 1-55). The tunica propria around them appears to thicken, and the goblet 

 cells in the neck of the degenerating gland, after becoming flattened, produce a solid 

 strand. The strand then ruptures and the detached fundus becomes cystic. Subse- 

 quently it shrinks to a small nodule surrounded by dense connective tissue, and 

 ultimately disappears. This degeneration is said to be limited to the fifth and 

 sixth months. 



The lumen of the normal vermiform process in the adult, when empty, 

 is thrown into folds, between which are deep pockets; but the normal con- 



