STRUCTURE OF MUSCULAR TISSUE. 807 



analogous to ptyalin (Piotrowski). 2. A coloring matter similar to, if not 

 identical with, haemoglobin. 3. Creatiu ( 54), and perhaps creatiuin, 1 bypo- 

 xanthiu or sarkin, xanthin, and tauriu. 4. Inosinic and uric acids. 5. Sugar, 



FIG. 290. 



Portion of an elementary Muscular Fibre from one of the abdominal muscles of the White Mouse, 

 with four dark-bordered fibres (a) crossing over its surface. A capillary vessel, 6, is also seen with fine 

 nerve-fibres distributed to it. To avoid confusion, a few only of the transverse markings of the muscle 

 are represented. Two of the dark-bordered nerve-finres (c), pass over the elementary fibre, to be dis- 

 tributed to adjacent fibres. One dark-bordered fibre (over d) is lost among several pale nucleated fibres. 

 Pale nucleated fibres are seen ramifying in several places upon the surface of the elementary fibre, but 

 beneath the dark-bordered nerve-fibres and capillaries. It will be observed that a fine fibre, which 

 seems at the upper part of the figure to be but one of the outlines of the tubular membrane of one of 

 the dark-bordered fibres, leaves the dark-bordered fibre and passes to the capillary vessel (over e). This 

 arrangement, in which a dark-bordered nerve-fibre distributed to muscle divides into bram-hes, one of 

 which passes to a vessel, while the other ramifies upon a muscle, is frequent. The capillaries, dark- 

 bordered nerve-fibres, and pale nucleated fibres here represented, can be completely stripped ofT from the 

 surface of the sarcolemma without tearing that membrane. Of the structures, therefore, represented 

 in this drawing, not one, according to Dr. Beale, can lie beneath the sarcolemma. (X 700.) (After 

 Beale.) 



inosite, glycogen, and dextrin. 6. An isomeric modification of lactic acid, 

 termed para- or sarco-lactic acid, acetic, formic, and butyric acids. 7. Salts, 

 which, as obtained from the residue of broth, consist in 100 parts 2 of 



26.27 S0 3 359 



Cl, 1.63 



Ka, . . . .9.40 

 KaO, .... 40.10 



2CaO,PO 5 , . . . 3.06 

 2MgO,P0 5 , . . . 5.76 

 2Fe 2 O s ,P0 6 , . . .057 



8. A small proportion of fat. 9. Water, carbonic acid, and oxygen gases; 

 and, lastly, various compounds derived from the tissues which are insepa- 

 rably united with the muscular tissue, as protagon proceeding from the ner- 

 vous, gelatin from the connective, and elastiu from the vascular tissue. The 

 composition of muscle as a whole is thus given by Kiihne, after Lehmann : 



Water, 74.0 80 



Solid constituents, 26.0 20.0 



Albuminous substances insoluble in water (myosin, sarco- 

 lemma, nuclei, vessels, and elastic fibres), . . . 15.4 17.7 



Gelatin, 0.6 1.9 



Albuminates of soda, coagulating at 113 F., . . . 2.2 3.0 



Creatin, 07 14 



Fat, 1.5 2.30 



Lactic acid, 1.5 2.30 



Phosphoric acid, 66 0.70 



Potash, 0.50 54 



Soda, 0.07 0.09 



Chloride of Sodium, 0.040.09 



Lime, 0.02 03 



Magnesia, 0.04 0.05 



1 Naurocki, Fresenius's Zeits. f. Analyt. Chemie, 1865, p. 330, denies the presence 

 of the latter, or that any conversion of creatin into creatinin occurs during exercise. 



2 Kiihne, Physiol. Chemie, 1868, p. 307, in which work a very complete account of 

 the chemistry of muscle is contained. 



