94 PHYSIOLOGY CHAP. 



fact that the wave of negativity at the point of the muscle 

 stimulated appears hefore and precedes the wave of contraction. 

 These particles probably lie chiefly in the isotropous layers which 

 take no active part in contraction. The thermogenic particles, 

 on the contrary, are in close contiguity with the inogcnic particles, 

 which are represented by the doubly refracting elements of the 

 anisotropous layers, on which the specific function of the muscle, 

 i.e. contraction, depends. According to Engelinann's theory this 

 is due to the conversion of heat into work. 



Verworn (1895), starting from a hypothesis put forward by 

 Berthold (1886), has formulated another theory of contraction, 

 which includes all the movements of all forms of living matter, 

 from amoeba to muscle. On this theory movement is due to 

 changes in the surface tension of the histological elements of 

 which the muscle fibrils consist (isotropous and anisotropous 

 discs) ; these changes in surface tension are due, according to 

 Verworn, to chemical processes. 



A similar theory, by which muscular contraction is referred to 

 changes of surface tension, has been put forward by other physio- 

 logists, as d'Arsonval, Imbert, Bernstein, Jensen, and Galeotti. 

 Galeotti holds (1906) that the changes in surface tension of the 

 different muscle elements are due to electrochemical phenomena. 



None of these theories, however, take into account the whole 

 of the active changes concomitant with muscular activity. 



BIBLIOGRAPHY 



Structure of Muscle and its Visible Changes during Activity : 



ENGELMANN. Pfliiger's Archiv, xi., 1875, xxv., 1881. 



RANVIER. Lemons d'anatoniie gunerale sur le systeme musculaire. Paris, 1880. 



ROLLET. Denkschr. der AViener Akademie, xlix. and li., 1885, Iviii. 1891. 



Mechanical, Thermal, and Electrical Activity of Muscle: 



HERMANN. Handbuch der Physiologic, i. 1879. 



CH. RICHET. Physiologic des muscles et des nerfs. Paris, 1882. 



BIEDERMANN. Elektrophysiologie. Jena, 1895. (English translation by F. A. 



Welby, 1896.) Ergebnisse d. Physiol., II. Part 2, 1903. 

 A. FICK. Mechan. Arbeit und Warmeentwickelung bei der Muskeltatigkeit. 



Internat. wiss. Bibliothek, 1882. 



ROSENTHAL. Allgemeine Physiol. der Muskeln und Nerven. Leipzig, 1899. 

 W. EINTHOVEN. Pfliiger's Archiv, lx., 1905 ; Arch, intern, d. Physiol., iv. 1906. 

 I. BERNSTEIN. Pfliiger's Archiv, Ixxxi., 1901. 

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 HOFMANN. Pfliiger's Arch., xciii., xcv., ciii., 1902-4. 

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Chemical Composition and Metabolism of Muscle : 



HALLIBURTON. Text-book of Chemical Physiology and Pathology, 1891. 



NEUMEISTER. Lehrbuch der physiologischen Chemie, 1895. 



H. WINTERSTEIN. Pfliiger's Archiv, cxx., 1907. 



v. FURTH. Ergeb. d. Physiol., I. Part 1, 1902 ; II. Part 1, 1903. 



