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Dr. G. Thin. Anatomy of the Skin. [Jan. 16, 



Various methods have been recommended by histologists for the 

 demonstration of the nltimate fibrillas of fibrous tissue, chiefly with 

 reference to those of tendon bundles. 



If I may judge by my own preparations of skin and by the figures 

 published in histological works, the fibrillae of the cutis bundles are 

 very seldom seen. The appearances usually observed in skin hardened 

 by chromic acid and alcohol are unfitted for a study of the fibrillae. In 

 such specimens the bundles are more or less broken up, but the 

 individual fibrillas are not, as a rule, isolated. 



I found that they were well shown by the following method : — A 

 portion of fresh skin, with the panniculus adiposus attached, was 

 pinned to a piece of cork, in the manner already described, and treated 

 in the same way, with the exception that this time glycerine, instead 

 of chloride of gold solution, was used for saturation. When the 

 saturated cutis tissue had been laid bare, the whole was placed in 

 glycerine and allowed to remain in it for several days. Small portions 

 were then teased out in glycerine, stained by picro-carminate of 

 ammonia and examined in glycerine. In such preparations the 

 secondary bundles were found isolated, the contours of the primary 

 bundles not being preserved. In the secondary bundles the fibrillse 

 were seen more or less distinctly, in some of them with perfect distinct- 

 ness. (See fig. 8.) 



In the gold preparations the following facts regarding the disposi- 

 tion of the elastic fibres were noted : — 



If a portion of skin is hardened in bichromate of potash, and the 

 sections moderately stained by eosin, all the large elastic fibres are 

 stained much more intensely than the bundles, and it is then observed 

 that they lie on the surface of the bundles, and run parallel to them. 

 In the gold preparations, after maceration in formic acid, further 

 details regarding the fibres can be detected. It is then seen that there 

 is a close network of minute elastic fibres, of which I have observed 

 no traces in eosin-stained bichromate preparations, on the surface of 

 the bundles, and that at certain points the larger fibres give oh 

 branches which join this network. At these points the network is so 

 dense over a small defined space that the size of the meshes is nearly 

 equalled by that of the fibres. 



Rollett, in the memoir referred to, states that the bundles are 

 embraced by elastic fibres, and that the latter send branches into the 

 substance of the bundles. I am able to confirm this statement, and 

 to extend it. In some of the gold and formic acid preparations, I 

 have observed that the elastic fibres which penetrate the bundles enter 

 between the primary bundles, and that the primary bundles are 

 embraced by the fibres which entwine them very closely. I have 

 never observed an elastic fibre penetrate a primary bundle. 



The relation of the elastic fibres to the primary bundles is shown in 



