FIBKES; CONNECTING TISSUE. 21 



posited by the periosteum in certain stages of perios- 

 titis. Senile opacity of the cornea is likewise ex- 

 plained by the appearance of oil-globules in the inte- 

 rior of its plasmatic cells. Finally, the researches of 

 Virchow tend to prove that all, or nearly all, of the 

 morbid formations developed in the meshes of the 

 connecting tissue throughout the body, are traceable 

 to the perverted growth of plasmatic cells. 



Connecting tissue, then, is made up of the three connecting 

 elements just studied, mingled together in variable 

 proportions, and, with them, of vessels and nerves, 

 also variable in number. But it is to be observed 

 that these latter exist in connecting tissue as accessory vessels. 

 elements only. Thus, the numerous vessels habitually 

 formed in certain layers of connecting tissue, as for 

 example in that which underlies the mucous mem- 

 brane of the intestinal canal, or some portions of the * 

 external integument, have nothing whatever to do 

 with the nutrition of the connecting tissue around 

 them ; they merely pass through it to their ultimate 

 destination, and are proportionate in number to the 

 importance of the function to which they minister 

 whether they furnish materials for important secre- * 

 tions, as in the one case, or in the other, as bearers of 

 caloric, are destined merely to keep up the heat of a 

 part. 



In the substance proper of connecting tissue the 

 phenomena of nutrition are of rather a low order. 

 The simple diffusion of the nutritious fluid exuded 

 from an occasional blood-vessel suffices to keep up the 

 vitality of the elements which compose it. This is 

 confirmed by examination of the structure of a tendon, 



