1908-9. | MICROCHEMISTRY OF STRIATED MUSCLE. 415 
ing Figs. 32-38, which illustrate the phosphate reaction, with Figs. 16-22 
which represent the distribution of the chlorides, one may determine 
what the localization of the phosphates is. 
Next to potassium the phosphates are the most abundant inorganic 
constituents of striated muscle. Consequently the microchemical deter- 
mination of their distribution is important. Invariably results analogous 
to those obtained in the chloride and potassium investigations, show the 
distribution of the phosphates to be the same as in the case of the 
chlorides and potassium salts. A most clearly marked precipitate 
possessing a granular character occurs along the edges of the dim bands, 
and a more faintly colored reaction at the central part indicates 
Hensen’s line (Fig. 34). This represents a typical distribution and 
when, as in Fig. 33, the phosphates seem to occupy the whole light 
band, it is to be explained by the fact that this structure has become so 
narrowed that its appearance is obliterated by the juxtaposition of the 
lines of the precipitate which really occur in the edges of the dim band. 
The disposition of the phosphates in the wing muscle, too, bears a 
striking resemblance to that already demonstrated in the case of the 
chlorides and the potassium. Comparing Fig. 28 with Fig. 37, which 
respectively represent the distribution of the potassium and the phos- 
phates on the borders of the light band, one sees the same localization 
obtaining in both, and further in Fig. 22, which represents the distribu- 
tion of the chlorides there is an approximation to the same condition. 
A comparison of Figs. 21 and 35 likewise reveals an analogous 
disposition of the chlorides and phosphates in the dim band, and the 
potassium shews a strikingly similar arrangement in Fig. 25. 
Occasionally in the wing muscle fibres there is a tendency which is 
also met with in the potassium preparations, towards an irregular 
distribution of these salts in the light band. This departure from a 
regular arrangement of these inorganic constituents has been observed 
only in this part of the fibril, never in the dim band where the. precipi- 
tate always possesses a distinctly longitudinal striation, and usually 
a definite granular character. 
From the foregoing observations it is apparent that the chlorides, 
the phosphates and the potassium have an analogous distribution and it 
is justifiable, therefore, to conclude that the definitely localized arrange- 
ment displayed by all of them is associated in some way with activity 
of the muscle. 
