238 B. MELLAND. 



transverse view there are thus seen small polygonal areas separated 

 by clear lines, each polygonal area corresponds to a sarcous element. 



Cohnheim's areas may be described as the appearances produced by 

 coagulation and splitting of the matrix along the guide lines formed 

 by the transverse network ; they represent an end view of sarcous 

 elements, and are post-mortem phenomena (diag. 9). 



Previous Views. 



I think it unnecessary to give a historical account of the different 

 views which have been published with regard to the structure of the 

 striped muscle fibre. 



An epitome of the historical results may be found in Sch'afer's 1 paper 

 on the leg muscles of the water-beetle ; or by the same author in 

 ' Quain's Anatomy,' 9th ed. 



Preference has already been made to most of the appearances des- 

 cribed by different observers, and the way in which these appearances 

 may be explained as caused by the presence of a highly refracting 

 network. 



The relation of this network to Krause's 2 views may be noticed. 

 Krause's "muskel-kastchen" are bounded above and below by Krause's 

 membrane, and laterally by the boundaries of Cohnheim's areas. 

 Briicke 3 regards the isotropous lines which traverse the anisotropous 

 disc as optical sections of the partitions between " muskel-kastchen." 

 These partitions correspond with the longitudinal bars of the network 

 and with Schafer's rods. The alternation of bright and dim transverse 

 bands has been looked upon by several observers as an optical effect, 

 and not due to any anatomical differentiation here present. 



Heppner 4 and Strieker look upon the bright band as the expression 

 of total reflexion, which occurs at the line of demarcation between 

 Krause's membrane and the chief substance of the fibre. 



Bowman suggested that the transverse striping shown by the fibrillee 

 was caused by the moniliform shape. Haycraft 5 has recently developed 

 this view, and extended it to the whole fibre. 



Striped muscular fibres are met with in the animal kingdom, 

 from the Coelenterata upwards; there is no reason to suppose that the 



1 Loc. cit. 



2 " Ueber den Bau cler quergestreiften Muskelfaser," 'Zeitschr. f. rat. Med.,' xxiii. 



8 • Quain's Anatomy,' p. 127 ; and " Muskelf. im polarisirten Licht," ' Wiener Denkschr.,'xv. 

 * * Strieker's Handbook ' (Syd. Socy.), p. 548, vol. iii. 

 11 'Quart. Journ. Micr. Sc.,' April 1, 1881. 



