572 THE INTESTINAL CANAL, BY E. KLEIN AND E. VERSON. 



which run up between the Lieberkiihnian glands, and, espe- 

 cially near the free surface of the mucous membrane are not 

 unfrequently connected by a few transverse fibres; and, on the 

 other hand, strong fasciculi, as many as twelve fibre cells in 

 thickness, which penetrate the villi, and extend throughout 

 their whole length. The muscular fasciculi in some instances 

 enter the villi in the form of separate cords, but in others 

 (especially in the smaller villi) first intercommunicate and 

 diverge from one another at the bases, so that a double layer of 

 muscular fasciculi may almost always be distinguished. One, 

 lying close to the central lacteal, and helping with the epithe- 

 lium to form its wall, the other running upwards in the paren- 

 chyma of the villi, traversing the meshes of the adenoid tissue, 

 and frequently intercommunicating by anastomosing oblique 

 fibre cells (His). The number of such fasciculi may amount to 

 twenty or more in a single villus, as is well seen in the dog and 

 cat, in which the longitudinal section of a villus often presents 

 from seven to ten fasciculi in close proximity. 



In the almost mature embryoes of guinea-pigs, instead of 

 completely formed villi, we find solid papilliform masses of 

 cells, with other similar structures presenting a central cavity 

 extending for a variable distance towards the apex. In the 

 latter a band of muscular fibres may be demonstrated, besides 

 a few vascular loops, which, proceeding from the muscularis 

 mucosse, arch over the apex of the csecal extremity of the 

 cavity, and return again to the muscularis mucosae. I have 

 obtained a preparation exhibiting similar features, from an 

 adult cat, and I believe that this affords an explanation of the 

 statement made by Bonders,* that transverse muscular fibres 

 are present at the apices of the villi. I have myself not un- 

 frequently seen them in the child, cat, and rat, and refer them 

 to the above-mentioned loop running immediately beneath the 

 free extremity. The fibre cells of the muscularis mucosse are 

 shorter and more slender than those of the muscular coat of the 

 intestine, being, according to Moleschott, scarcely 0*06 of a milli- 

 meter long. The entire thickness of the muscular layer of the 

 mucous membrane in man does not in general exceed 0*021 



* Physiologic, Band i. 



