194 GENERAL ANATOMY. 



set are aggregated, as the caruncula lachry mails, the aryte- 

 noid gland, the aggregated glands of the ilium, &c.; finally, 

 others are compound and have multiplied lacuna or ramified 

 ducts, and greatly resemble glands: such are the tonsils, the 

 molar glands, the prostate, the glands of Cowper, &c. 



266. The little eminences called papilla? or villosities that 

 are seen on the free surface of the mucous membrane appear 

 to be designed, like the depressions of which we have been 

 speaking and to which, in number, they are in an inverse 

 ratio, to increase the surface; but, in the one as well as the 

 other of these dispositions, the texture and functions of the 

 membrane are remarkably modified. These eminences, called 

 villosities, in consequence of the comparison drawn by Fallopius 

 between the internal membrane of the intestines and velvet, 

 and named papillae, on account of their supposed resemblance 

 to a button or nipple, do not essentially differ with each other; 

 both are projections of the membrane more or less fine, and 

 the greater part hardly visible to the naked eye. 



The most voluminous of these elevations are called papillae, 

 such are those that fill the cavity of the teeth, commonly 

 called their pulp; those smaller ones that bristle the two ante- 

 rior thirds of the tongue, and those, still smaller, that are per- 

 ceived on the gland of the penis, of the clitoris, &c. These 

 elevations belong to the corium of the mucous membrane, 

 furnished in these places with a great number of nervous 

 threads and small branches of blood-vessels, among which the 

 little veins present an erectile disposition. In parts provided 

 with papillae, the mucous membrane is furnished with a dis- 

 tinct epidermis, called epithelium, on account of its covering 

 the papillae. 



267. The villosities, whose existence is very general, but 

 which are nowhere more numerous, larger, or more apparent, 

 than in the pyloric half of the stomach, the small intestine, 

 and in the beginning of it in particular, are still smaller than 

 the papillae. 



These villosities, which may with justice be styled the radi- 

 cles of animals ^are, little foliaceous prolongations of the internal 

 membrane of the digestive canal, whose form and length vary 



