110 DESCRIPTION OF THE PLATES. 



PLATE I. Fig. G. Extremity of a villus, with its absorbent vesicles 

 distended with chyle, and the trunks of its lac- 

 teals seen through its coats. 



Fig. 7. Protective epithelium cells from a villus in the dog. 



Fig. 8. Protective epithelium cells cast off preparatory to 

 absorption of chyle ; instead of nuclei, they pre- 

 sent, in their interior, groups of globules. 



Fig. 9. A group of the same cells adhering by their distal 



extremities. 

 Fig. 10. Secreting cells thrown out of the follicles of Lei- 



berkiihn during digestion. 



Fig. 11. Diagram of mucous membrane of jejunum when 

 absorption is not going on. a Protective epithe- 

 lium of a villus. b Secreting epithelium of a 

 follicle, c c c Primary membrane, with its ger- 

 minal spots or nuclei, d d. e Germs of absor- 

 bent vesicles. / Vessels and lacteals of villus. 

 Fig. 12. Diagram of mucous membrane during digestion 

 and absorption of chyle, a A villus, turgid, 

 erect ; its protective epithelia cast off from its 

 free extremity ; its absorbent vesicles, its lacteals 

 and blood-vessels turgid, b A follicle discharg- 

 ing its secreting epithelia. 



PROCESS OF ULCERATION IN ARTICULAR CARTILAGE. 



PLATE I. Fig. 13. a A section of articular cartilage and absorbent 

 membrane. In the lower part of the section the 

 cartilage corpuscles retain their natural size 

 and appearance ; as they approach the rugged 

 ulcerated edge, they increase in size, and con- 

 tain numerous young cells, apparently the pro- 

 geny of their nuclei ; beyond this edge, rounded 

 masses of cells, originally contained within the 

 cartilage corpuscules, are seen embedded in the 

 cellular absorbent mass. 



