a1 7 Saree 
1908-9. ] MICROCHEMISTRY OF STRIATED MUSCLE. 4il 
that there is an interruption in the light band which rarely contains any 
of the darkened sub-chloride of silver. Each stria is composed of fine 
granules, which are the colored particles. 
The chlorides, however, are not always confined to the dim band,. 
and although amongst the preparations studied, this seemed to be the 
distribution, which most frequently obtained, the reverse picture is 
often met with, the chlorides being aggregated at the junction of the light 
and dim bands, while the dim band itself appears comparatively free from 
any reaction. In Fig. 22, for example, the silver salts are shown massed 
along the upper and lower border lines of the light band, and only 
a few scattered granules of a faint colour appear to lie in the dim band. 
Fig. 21 represents the chlorides occurring simultaneously in both the 
light and dim elements of the muscle fibre, and while the greater part 
of this inorganic material appears in regularly distributed vertical lines 
in the dim band, frequently these lines are continued into the light 
band. 
Since the reaction may be well marked on the borders of the 
light band and the dim band be devoid of any coloration, and vice 
versa, the result can hardly be due to a redistribution caused by the 
advance of the penetrant acid being more rapid than that of the silver 
nitrate for in these cases a diffuse reaction also occurs. Hence it is 
inferred that there is an alteration or rearrangement in the disposition 
of these salts, which has some definite relation to the activity of the 
muscle. 
It can scarcely be doubted but that these various striations 
represent the arrangement of the chlorides as they obtain in the living 
muscle. It is true that striae may result (as in the Boehm-Liesegang 
phenomena) from a uniform distribution of inorganic salts in solutions 
of definite consistency as has been experimentally shewn by treating 
mixtures of albumen and of gelatine in glass tubes or plates with . 
certain silver salts and then exposing the preparations to the sunlight. 
In these cases, however, the strize and the interstriate zones are of 
varying widths, being wider and less sharply defined as the reaction 
progresses in the direction of the line of diffusion ; also the depth of the 
reaction in each gradually decreases from the central point peripherally. 
In the muscle, on the other hand, the tone of reaction throughout 
the individual fibres is constant and the striations are sharply defined. 
When variations in the width of the strie do occur they may be 
explained as due to the differences in the width of the dim bands. 
