214 



MANUAL OF HISTOLOGY. 



that we are probably dealing with a peculiar property inherent universally 

 in these elements. 



Let us now return for a moment to the connective-tissue corpuscles 

 we were observing in the frog. It is only necessary to add a drop of 

 water to the preparation to produce a great change in the nucleus, and 

 greater in the protoplasm, which contracts around the latter to 'a kind 

 of fine network. Acetic acid has even a more lasting effect. It causes 

 the nucleus to appear darkly and clearly in the shrunken protoplasm, 

 and gives rise to a distinctly marked halo around the cell. This boundary 

 line encircling the corpuscle formed of altered intermediate substance 

 may simulate a membrane upon it. 



130. 



After what has just been remarked, it Will be seen that for the present 

 we must abandon all hope, in studying human connective-tissue, of meet- 

 ing these cells in an unchanged condition. When most fortunate, we can 

 only obtain them just dead, and as yet but slightly altered. Acetic acid, 

 which was formerly much used in studying the connective-tissue cells, 

 exercises a strong gelatinising influence upon the intermediate substance, 



Fig. 208. -Tail tendon of a young rabbit. A, the tendon 

 stretched, magnified 200 times. B, a. less tense tendon en- 

 larged 300 diameters; a, cells of the tendon filled with fat 

 at 6 ; c, fine elastic fibres. 



by which the cellular elements are distorted and assume the most extra- 

 ordinary forms. This reagent has been the cause of numerous errors, and 

 has regulated for many years our views in regard to connective-tissue. 

 -Now, what is known at the present day of these elements ? 

 We must confess not much. Something we have, however, gained 

 from more accurate investigation. The connective-tissue cells of the 

 mature body are frequently (though not invariably) flattened structures, 

 nucleated plates displaying still some protoplasm in the neighbour- 

 hood of the nucleus as a rule, but so thin at their borders as to require 



