71 



The anatomy of these organs, has heretofore been involved 

 in a considerable degree of confusion, and though it is not yet 

 satisfactorily established, enough has been done to enable us to 

 make a division of them into classes, so as to render the descrip- 

 tion of them more intelligible. 



From the researches of recent observers, they may be 

 divided into two classes. The first, comprising the mucous 

 follicles or mucous cryptae, and mucous glands. The second 

 class consisting of some vesicular bodies, which may be sub- 

 divided into, 1st, The glandulae solitarise, (glands of Brunner, 

 of some anatomists,) and 2d, The so called glandule agmina- 

 tae, or glands of Peyer. The mucous follicles or crypts, and 

 the mucous glands forming the first class are generally spread 

 throughout the mucous membranes, and seem to differ from 

 each other but little, except in regard to the degree of their 

 development. 



The mucous follicles are entirely microscopical ; and were 

 first particularly described by Lieberkuhn in the small intestines, 

 where they are frequently called the follicles of Lieberkuhn. 

 If a portion of the mucous membrane of a small intestine be 

 well washed, we may readily discover, by means of a simple 

 microscope, around the basis of the villi an extraordinary num- 

 ber of orifices not visible to the naked eye, which are the open- 

 ing of Lieberkuhn's follicles ; these openings are about eight or 

 ten times as large in diameter, as the red particles of the blood.* 

 Sometimes these openings are so close and numerous, that the 

 space between the orifices is scarcely so broad as the orifices 

 themselves ; generally, however, they are more widely sepa- 

 rated, in which case they give a spongy appearance to the 

 membrane. These follicles of the small intestines, which were 

 Fig. 140.* observed by Lieberkuhn, appear to be the 

 exact counterpart of the tubular follicles 

 observed in the whole extent of the mucous 

 membrane of the large intestine by Dr. 

 Boehm, and in the mucous membrane of 

 the stomach by Dr. Boyd. C, Is an enlarged 

 view of the tubular follicles of the large 



* Mailer's Physiology, p. 260. 



