48 ORGANS OF DIGESTION. 



mina or follicles now under consideration. The following ex- 

 tract will explain the difficulty which still exists in regard to a 

 proper conception of the latter. 



" The mucous glands, called also follicles or cryptas mucosae, 

 are to the membranes of that name what the sebaceous follicles 

 are to the skin ; that is to say, folds of the mucous membrane 

 in form of a cul-de-sac, whose orifices open upon that mem- 

 brane. These follicles have not yet been discovered over the 

 whole surface of the mucous membrane ; but here, as with the 

 skin, analogy leads us to admit them. It is not long since they 

 have been discovered in the pituitary membrane, where their 

 existence had been denied. Be this as it may, we shall use the 

 same observation upon these glands that was made on the se- 

 baceous, viz. the impossibility of making an exact dissection of 

 the capillary tissues does not allow us to discover all .the forms 

 of animal matter; but wherever a particular humour is found 

 in a tissue, we are forced to conclude that this latter is orga- 

 nized in such a manner as to be able to produce it, and when 

 in place of one humour we meet with many, we must acknow- 

 ledge that the tissue is complex. Such is precisely the case 

 with the mucous membrane of the digestive canal, and espe- 

 cially of the stomach, which could have a form of animal mat- 

 ter calculated to furnish digestive juices, although no gland 

 destined to that purpose is discoverable."* This desideratum 

 of positive evidence, instead of the inductive, is clearly supplied 

 by my preparations. 



In infancy, especially, the mucous glands have a sensible 

 thickness, which enables us to see them, but the smallest of them 

 require the aid of a microscope, and appear to have been de- 

 scribed by Galeati.t As the paper is not to be had in any of 

 the public libraries of this city, I can only quote from it on the 

 current authority of anatomical works. In a note to the anato- 

 my of the human body by Sir Charles Bell, article Intestine, it 

 is stated as follows: "It has been supposed that the fluids ex- 

 creted from the surface of the intestines were furnished by very 

 minute foramina, (which are visible by particular preparations,) 

 in the interstices of the villi. See the letter of Malpighi to the 

 Royal Society of London on the pores of the stomach, and the 



* Broussais' Physiology. First American edition, p. 413. 



\ De cornea ventriculi et intcstlnorum tunica. Comm Bonon. 1745. 



