32 1 NOTES AND MEMORANDA. 



By the term hmdle, or secondary bundle, Dr. Thin designates the 

 ordinary bundle of authors, which is more or loss consiiicuous in all 

 preparations of skin, and which is analogous in structure and size 

 to the bundles as usually described and figured in tendon-tissue. The 

 element described by Eollett as " connective-tissue fibre " he desci-ibes 

 as primary bundle, to distinguish it more markedly from the fibrillfe 

 which compose it. When groups of secondary bundles are isolated, 

 each group being composed of several secondary bundles, he terras 

 the group a tertiary bundle. 



These elements can be isolated by first saturating the cerium with 

 chloride of gold solution, and then macerating the tissue in acids. 

 Portions of skin, with a thick layer of the panniculus adiposus, were 

 taken fresh from the mamma of a middle-aged woman, which had 

 been removed for a tumour of the gland, the portions of skin chosen 

 being well clear of diseased tissues. The stretched skin was pinned 

 down to a cork board, the under surface uppermost, and then saturated 

 with ^ per cent, chloride of gold solution. From time to time dif- 

 ferent thicknesses of the fatty layer were removed as the solution had 

 had time to penetrate into the tissue, until, finally, the deejjer layer of 

 the cutis proper was laid bare. The tissue, still extended, was then 

 placed in fresh gold solution for several hours. The object of the 

 manoeuvre was to secure the penetration of the fluid through the 

 bundles, whilst these were still extended in their natural condition. 



After a due action of the gold, the skin was cut into small pieces, 

 which were then treated by acetic acid, and then the strength of the 

 acetic acid raised to 20 per cent, of the ordinary concentrated acetic 

 acid of commerce. Other portions were treated by formic acid. Some 

 successful preparations were obtained from portions macerated first for 

 a few days in a mixture of one part formic acid, of specific gravity 

 1 • 020, and one of water, and then in the undiluted acid for some days 

 longer, but a strict adherence to these strengths was not found necessary. 



Portions of the corium thus prepared were teased out in glycerine 

 and examined directly or after staining by different dyes. Staining by 

 picric acid was found very advantageous. 



In this way he was able to isolate in a condition favourable for 

 study the primary, secondary, and tertiary bundles. Generally speak- 

 ing, although not invariably, the tertiary and secondary bundles were 

 best seen in the tissues macerated in acetic acid, and the secondary 

 and primary bundles in those treated by formic acid. 



Numerous elastic fibres were isolated by both methods, the finest 

 fibres more particularly in the formic acid preparation. 



Various methods have been recommended by histologists for the 

 demonstration of the ultimate fibrillte of fibrous tissue, chiefly with 

 reference to those of tendon bundles. Judging by the figures pub- 

 lished in histological works, the fibrillfe of the cutis bundles are. 

 Dr. Thin thinks, very seldom seen ; the appearances usually observed 

 in skin hardened by chromic acid and alcohol are unfitted for a study 

 of the fibrillfe. In such specimens the bundles are more or less broken 

 up, but the individual fibrillfe are not, as a rule, isolated. He found, 

 however, that they were well shown by the following method : — A 



