STRUCTURE OF STRIATED MUSCLE. 547 



structure was obtained, and it was concluded that sarcous 

 elements, surrounded by a fluid intervening substance, and 

 laminated (as disks) like the layers of bricks in a wall, com- 

 posed the muscular substance. 



Kolliker* has however more recently opposed Cohnheim's 

 description. He maintains that the areas described by Cohii- 

 heim are the transverse sections of muscular columns, which 

 he again regards as composed of smaller fasciculi of fibrils- 

 His account therefore coincides with that given by Leydig and 

 Rollett. 



From the description given by Kiihne (vol. i., p. 202, of this 

 Manual), it appears that his opinion in regard to the internal 

 structure is essentially the same as that which may be easily 

 deduced from the account given by Cohnheim. 



Such was the state of our knowledge on this subject till the 

 appearance, nearly coincidently, of the works of Krause and 

 Hensen foreshadowed an essentially different explanation. Ac- 

 cording to Hensen,f the structure of muscular fibre is some- 

 what as follows : In the primitive fibre of a quiescent muscle, 

 each transverse stria is divided into two halves by a dark line. 

 This line is the expression of a fine disk (median disk). There 

 is moreover, not simply an alternation of a highly refractile sub- 

 stance, the intermediate substance, but after the first half of the 

 transverse disk there follows a feebly refractile substance, the 

 median disk ; then the second half of the transverse disk ; and 

 lastly, the intermediate substance. 



KrauseJ gives a different explanation. Each fusiform fibre 

 (muskel-spindel), according to him, consists, independently of 

 the sarcolemma, of a very large number of muscular cases or 

 compartments (Muskel-kastchen). Each muscle case contains a 

 muscle prism, composed of anisotropal material, which almost 

 entirely fills the muscle case. The form of the muscle prisms 

 (sarcous elements) is that of a multangular 'column, transversely 

 truncated above and below, the transverse diameter of which 

 varies, whilst the height of the muscle prisms, like that of the 



* See his Manual of Histology, 1867, and the Zeitschrift fur u'ixstn- 

 schaftliche Zooloyie, Band xvi. 



f Arbeiten aus dem Kiekr physioloyischen Institut, 1868. 

 1 Zcitschnft fur Bioloyie. 



N N 2 



