134 LECTURE V. 



there afterwards arises a tissue with its basis-substance 

 mapped out by large elastic networks with extremely 

 compact and tough fibres. 



It has not up to the present time positively been 

 determined, whether in the course of this transformation 

 the condensation '(sclerosis) of the walls of the cells pro- 

 ceeds to such a pitch as entirely to obliterate their 

 cavity, and thus completely destroy their powers of 

 conduction, or whether a small cavity remains in their 

 interior. In transverse sections of fine elastic fibres, 

 it looks as if the latter were the case, and there is 

 therefore ground for the supposition, that in the trans- 

 formation of the corpuscles of connective tissue into 

 elastic fibres, nothing more than a condensation and 

 thickening, and at the same time a chemical metamor- 

 phosis of the membrane, takes place, but that ultimately, 

 however, a very small portion of the cell-cavity remains. 

 What sort of a substance it is that constitutes the elastic 

 parts, has not been determined, because it is not possible 

 to accomplish their solution by any means ; with a part 

 of the products of the decomposition of this tissue we 

 are, indeed, acquainted, but nothing further is known 

 concerning its chemical constitution. But from this no 

 decision can be arrived at with respect either to its com- 

 position, or position in a chemical point of view with 

 regard to other tissues. 



This kind of transformation prevails to an extraordi- 

 nary extent in the skin, especially in the deeper layers 

 of the corium proper, and to it is chiefly owing the 

 extraordinary resistance of this tissue which we so 

 gratefully acknowledge when daily testing it in the soles 

 of our shoes. For the firmness of the individual layers 

 of the skin depends essentially upon the greater or less 

 quantity of elastic fibres contained in them. The most 

 superficial part of the corium immediately beneath the 



