Royal Physical Society. 4,1 



while the concave or inner aspect of the valve is, on the con- 

 trary, follicular. 



It is to the last Peyerian patch that we wish to direct espe- 

 cial attention ; for here we have developed an extremely com- 

 plicated structure, consisting of from fifteen to twenty pouches, 

 the whole forming a network of cells, and reminding us to a 

 certain extent, of the water cavities of the reticulum. This 

 large compound gland stretches itself continuously from a point 

 anterior to the extremity of the small intestine, to rather more 

 than two inches beyond the ileo-colic valve ; and it is from the 

 latter division of the patch that the anomaly (which is repre- 

 sented in the accompanying plate) proceeds. Seven of the 

 pouches are complete, and bounded by extremely attenuated 

 lamellae projecting from two to four lines beyond the surface ; 

 they are more or less polygonal, the openings of the first five 

 being large (Nos. 1, 2, 3, 4, 5), and nearly as broad as the calibre 

 of the cavities internally; the other two (6 and 7) have contracted 

 oval orifices, measuring only about half the width of the pouches, 

 within. From the right wall of the cavity, marked No. 1, 

 part of the tissues were removed, and subjected to microscopic 

 examination, when the glandular substance showed appear- 

 ances such as are ordinarily recognised in the agminated fol- 

 licles, while beneath the submucous tissue muscular fibres 

 were found, of the non-voluntary kind. Some of the cavities 

 contain secondary sacculi, but these are generally small, and 

 separated by very slightly developed septa ; at the upper part 

 of the sacculus, figured No. 5, is seen one of the secondary 

 pouches of a triangular form, and well defined. The eighth, 

 ninth, tenth, and eleventh spaces are represented by mere de- 

 pressions bounded by rudimentary partitions scarcely raised 

 from the surface ; the twelfth, thirteenth, and fourteenth are 

 more decidedly saccular, especially the first-named, which is 

 elongated, and shows traces of subdivision. Thus far all the 

 folds are lined within and without by follicles characteristic of 

 the compound intestinal glands ; the latter structures are fully 

 developed at every part, but acquire greater conspicuity as 

 they ascend the colon, in which situation they are less closely 

 packed together, and of larger dimensions. Finally, it only 



