5^ 



ELASTIC TISSUE. 



[SECT. 25. 



Stellate formative 

 cells, of fine elastic 

 fibres, from the 

 tendo-Achillis of a 

 newly-born child. 

 Magnified 350 times. 



great elasticity of this tissue, by which it supports very essentially 

 Fig. 20. the motory organs, and also plays an important part in 

 other respects, e. g., in the vocal cords. With regard 

 to its development, the supposition of Schwann, that 

 this tissue arises from cells, is rendered more and 

 more probable by the more recent investigations. 

 In fact, in all parts of the embryo which afterwards 

 contain elastic tissue, peculiar fusiform or stellate, 

 and sharply-pointed cells can be recognised, which, 

 by their coalescence, produce long fibres or networks, 

 in which the situation of the body, or central part, of 

 the original cell may for some time be distinguished by 

 a swelling of the fibre, with an elongated nucleus in 

 the interior. The fibres not unfrequently persist in 

 this condition of stellate anastomosing cells, or con- 

 nective tissue-corpuscles (Virchow), as, e.g., in the 

 tendons and the cornea, in ligaments and ligamentous 

 discs, in the corium, in mucous membranes, etc.; 

 in which places, moreover, fully formed elastic fibres 

 are generally present. In other cases, every trace of 

 their former cellular nature disappears, so that uni- 

 form fibres, or fibrous networks, arise. These may then persist 

 throughout life as fine elastic fibres and networks, or, by increase 

 in thickness, pass into the coarser form of this tissue. The homo- 

 geneous elastic membranes are nothing but close elastic networks, 

 the fibres of which have become so broad that only narrow spaces 

 remain between them. The fully developed elastic tissue appears 

 scarcely to be subject to any nutritive change of material; at any 

 rate, it is, in the ordinary sense, non-vascular, even when in large 

 masses. On the other hand, Virchoivs supposition, that the unde- 

 veloped forms of this tissue, particularly the connective-tissue-cor- 

 puscles, contain juices, and help in effecting nutrition, is obviously 

 well founded ; and we may, perhaps, be warranted in placing them, 

 physiologically, on a parallel with the fine canalicular system in 

 the bones and teeth ; on which account I will call them plasm-cells, 

 and their processes plasm-tubes. It is not known that the elastic 

 tissue is ever regenerated ; on the other hand, new formations of it 

 are not rare. 



The elastic fibres rarely appear in large masses, but are fre- 

 quently found intermixed with connective tissue, either in the form 

 of isolated fibres, or of networks of various kinds. As true elastic 

 organs, are to be mentioned — 



