1879.J Dr. G. Thin. Anatomy of the Shin, 255 



fig. 7, but the fibres are in reality more delicate than is shown in the 

 drawing. 



The dark very finely granular deposit produced by the reduction of 

 the gold chloride had a special relation to the elastic fibres, which was 

 best observed in portions of skin which had been macerated for a 

 longer period in 20 per cent, acetic acid. This relation will be under- 

 stood by reference to figs. 3, 6, 9, and 10. Strictly defined narrow 

 strips of this deposit were found investing the fibres, and this so 

 closely that it was only at points where it had been disturbed in the 

 preparation that the fibre itself could be observed. 



The appearances reproduced in figs. 3 and 10, in which fibres are 

 seen with deposit still adherent, illustrate this point very strikingly. 



In gold preparations large flat oval nuclei are sometimes seen 

 adherent to the surface of the bundle. The nuclei have the charac- 

 teristic slate colour, and around the nueleus a small ill- defined patch 

 of gold deposit is seen. 



This deposit could sometimes be seen to be continuous with that 

 surrounding an elastic fibre. This is shown in fig. 10. There is 

 no reason to believe that in such cases more of the cell than the nucleus 

 has been preserved, or that the gold deposit has any special relation 

 to cellular substance * The distinctly localised character of the 

 deposit around the elastic fibres supports the idea that the larger ones 

 are surrounded by an albuminous fluid, of a like nature to that shown 

 by gold preparations, to be present between the laminae of the cornea. 



Isolated tertiary bundles completely surrounded by elastic fibres 

 (fig. 5), are sometimes seen. 



The " spiral " fibre, as I have seen it on the bundles of the skin, is 

 an elastic fibre that encircles the bundles like a ring ; and it may con- 

 tinue to do so after the ring has been detached from other fibres, none 

 of which, indeed, may be found in the isolated bundle. 



The nature of the spiral fibre is still considered by some histologists 

 as undecided, and Ranvier regards its behaviour under picro-carminate 

 staining as against the view that it is an elastic fibre. In the prepara- 

 tion drawn in fig. 8, which had been stained by picro-carminate, a 

 typical spiral fibre was distinctly stained yellow by the pikric acid, 

 and was not stained by the carmine, behaving in this respect exactly 

 like any other elastic fibre. 



Confirmation of Rollett's views as to the structure of the bundles 

 is occasionally found in bichromate of potash preparations of skin. 

 Part of one of the most demonstrative preparations of this kind 



* In a paper read before the Royal Society in 1874 (" Proceedings," No. 155, 

 1874), I followed the view held by some histologists, that the gold deposit in such 

 preparations is indicative of cellular protoplasm, and described and figured (fig. 13) 

 an anastomosis of cells in the skin by means of elastic fibres. As will be observed 

 from the remarks in the text, I now interpret these appearances quite differently. 



