TISSUES OF THE BODY. 



213 



substance, which is gelatinous and transparent, first of all the fibrillse and 

 fasciculi of the connective-tissue (/, g) t as well as a network of extremely 

 delicate elastic fibres (h). Then the expected cells (a-e) are observed, 

 though not so close together as in our plate, but at rather greater inter- 

 vals. ^All of them are naked, and appear in several varieties. The 

 most usual form in which they are met with is that of a delicate proto- 

 plasmic structure in which no nucleus can be discerned, but in its place a 

 darker spot (a). The cells in question send off several processes which may 

 attain considerable length, and come into contact with those of neigh- 

 bouring cells (b). By very strong magnifying power there may be seen, 

 beside these longer processes, a large number of shorter and paler ones, 



Fig. 207. A portion of living connective-tissue, cut out from 

 between the muscles of the frog's thigh (strongly magni- 

 fied) . , a pale contracted cell with a dark lump in the in- 

 terior; 6, ramified corpuscles; c, a similar corpuscle with 

 vesicular nucleus; d and e, motionless, coarsely granular 

 cells; /, fibrillae; <;, bundles of connective-tissue; A, elastic 

 fibrous network. 



giving to the contour of the structure a regularly jagged appearance. 

 Other connective-tissue corpuscles preserve generally a more even outline, 

 and contain a vesicular nucleus (b above, c). By their processes, few in 

 number, they are connected with one another, as well as with the cells 

 belonging to the first variety. Finally, there appear other cells of a third 

 form, remarkable for the opacity of their protoplasm. They are usually 

 fusiform (d, e), and contain a vesicular nucleus. 



With the exception of the last mentioned and more coarsely granular 

 cells, connective-tissue corpuscles are endowed with the power of very 

 slow but unmistakable vital contractility, their form changes, processes 

 commence to make their appearance, elongate and unite with those of 

 neighbouring cells, and become again disunited. Nothing can be seen of 

 pre-formed paths for these processes ; the almost mucoid consistence of the 

 intercellular substance allows of free play to their motion in all directions. 



In other organs also, and in the bodies of many different animals, the 

 same contractile corpuscles of connective-tissue have been observed, so 



