132 DR. MITCHELL BRUCE. 



and presented at their lateral margins, not a straight optical 

 line, but an irregular ragged border. 



Such are the appearances presented by a fresh tendon 

 where the bundles are not parallel. I shall not as yet draw 

 any conclusion from them, but describe in the next place the 

 results obtained by other processes. 



Of these, the first I availed myself of was the one with 

 nitrate of silver. The fine tendons from the tail of the rat 

 were removed with care, and allowed to remain in a half-per- 

 cent, solution of the salt for two or three minutes, then trans- 

 ferred to a vessel of water placed in a bright sun, and when 

 coloured mounted as usual. Specimens of tendon so pre- 

 pared presented on examination a very fine superficial layer 

 of large polyhedral endothelial plates, the dark connecting 

 lines of which were more or less tortuous. In some of the 

 specimens where this endothelium was slightly marked, or 

 where it had been removed, either accidentally or by gentle 

 pencilling in serum with a camePs hair brush, before the 

 specimen Avas put into the silver solution, there was to be 

 seen evidently close under the endothelium of the surface a 

 system of clear branched spaces [Saftkandlchen) on a yellowish 

 brown ground. Yet another or third appearance was fre- 

 quently found on the silver specimens in the deeper parts of 

 the tendon ; in many of them prepared as above described only 

 here and there, but much more extensively and distinctly if 

 the pencilling process had been resorted to, and the brush 

 used with considerable freedom. This third appearance fully 

 corresponded to that found in the fresh tendon. The parallel 

 course of the bundles was seen, as befure, interrupted by 

 regularly disposed transverse lines, the only difference in the 

 two cases being that the lines were in these silver prepara- 

 tions dark instead of clear, and the surface of the bundles — 

 that is, the quadrilateral spaces bounded longitudinally by 

 the lines — clear instead of dark. In these specimens, also, 

 as in the fresh ones, the transverse lines of two or three 

 neighbouring bundles were frequently found to be con- 

 tinuous with each other laterally. The arrangement, there- 

 fore, exactly corresponded in tire specimen prepared by the 

 two processes. In some parts of the preparation a similar 

 terminal junction of the transverse lines could be made out 

 without difficulty at some depth beneath the surface of the 

 bundles. 



The next method of preparation which I made use of was 

 that with chloride of gold. Tendons from the same source 

 as before Avere allowed to remain in a half-per-cent. solution 

 of the salt until they assumed a bright straw colour, on an 



