540 Transactions of the Society. 



In numerous specimens a peculiar appearance of aerolated lines was 

 noticed, which generally followed the course of the fibres, but sometimes 

 ran rather obliquely across them. These looked very much hke long 

 interspaces, varying slightly here and there in width, that had been filled 

 with some fluid that had coagulated and imprisoned minute air-spaces. 

 One specimen was photographed for part of its course which was more 

 than double that depicted in the printed photograph No. 4. The slight 

 swellings are visible in the part represented. Several of these aerolated 

 spaces are also shown in the figs., especially fig. 2. They remain a 

 puzzle to me, but they led me to search most carefully for some perfect 

 minute vessels, and after spending much time over the sUdes I was 

 rewarded by finding a small vessel charged with rather coarse granular 

 contents lying between the fibres. It had been broken across in its 

 course, and separated only a very short distance from it were likewise 

 three small broken portions of the same vessel. The attempt to repro- 

 duce this by photography, photograph 5, has not been as successful as 

 desired on account of the non-actinic colour of the structure, hence it has 

 been figured more highly magnified, fig. 3. Whether the contents were 

 blood constituents greatly altered by the process of embalming or perhaps 

 by the injection of some preservative liquid is doubtful, but the ap- 

 pearance is sufficiently characteristic of its vascular nature. The use of 

 immersion lenses disclosed nothing more satisfactory, as regards the 

 granular contents, though some of the few separated granules seemed to 

 have a kind of halo round them. Thus far the examinations proved very 

 interesting. Two apparently different vessels or empty tubes were 

 dissociated from the fibres by the needles, but it appears to me they cannot 

 safely be said to belong to either the lymphatic or vascular systems, for 

 some parts of the muscle had been invaded by a mildew growth. 

 Curiously this mycelium had spread across the fibres and not in the 

 direction of their length. These two tubes appeared too large to be the 

 basic mycelium tubes connected with the smaller branches of what were 

 regarded as due to a growth of Penicillium from the few conidia found 

 lying amongst them. These vessels or tubes were photographed in 

 order to furnish an idea of their appearance, and on the nature of which 

 I do not venture to offer any definite opinion. Photograph 6. 



During the examination of many of the prepared specimens, where the 

 fibrous structures had been purposely compressed, the eye continually 

 glimpsed minute fibres of a different refractive power from the other 

 parts, running for a short distance in the substance of the muscle, and 

 then lost to view. This led me to endeavour to prepare some of the 

 specimens so that their course could be more completely followed. By 

 very careful focusing the fibres could now be traced through different 

 levels, although the plexus brought into view is figured in each drawing 

 as if it occupied only one plane. Figs. 4, 5 and 6. Without much hesita- 

 tion, I think these fine fibres must be regarded as nerve-fibres. They 

 were not seen in any of the specimens as long as the muscle structure 

 retained its fibrous appearance, but when it was softened, compressed, 

 and had assumed a more or less finely granular character, then 

 these delicate nerve-fibres were brought into view. The mode of pre- 

 paration that gave perhaps the best results was when boiled for ten 



