236 



SPECIAL HISTOLOGY. 



of Du Bois-Rej^rnond, and above all of Bowman. According to 

 the latter, a division of the muscular fibres into "discs" (fig. 92) 

 Fig. 92. i s quite as natural, although not so frequent, 



as that into fibrils, and that they may be con- 

 sidered as columns composed of such discs, 

 quite as correctly as bundles of fibrils. Were 

 a muscular fibre completely divided in the 

 direction of both the transverse and longitu- 

 dinal striae, rounded, angular, minute particles 

 would be produced, which may be termed 

 primitive particles, or " sarcous elements." In 

 the fibre, these elementary particles are con- 

 nected in both directions, the same particles 

 in the one case constituting a "disc," and in 

 the other a segment or joint of the fibrils. The 

 division into discs, upon which Bowman lays 

 especial stress, would in my opinion have been 

 of importance, had it occurred as frequently as that into fibrils, 

 .and also, occasionally, in recent muscle, but it is not so, — for in 

 the first place, nothing of the sort can ever be seen in recent 

 muscles of man and the higher animals ; and in the second 

 place, even in macerated, or otherwise manipulated fasciculi, the 

 breaking up into discs is an extremely rare phenomenon ; 

 whilst on the other hand, the isolation and exhibition of the 

 fibrils may be obtained, in almost every instance, by any one 

 at all conversant with the subject. Moreover, in transverse 

 sections of perfectly fresh living muscles, as for instance of the 

 thigh of a Frog, made by means of the double-bladed knife, 

 the transverse section of the fibrils is just as evident and 

 distinct as in dried muscles, whilst, in precisely similar longi- 

 tudinal sections, not a trace of the " discs" can be detected. 

 This fact at once sets aside all those views, according to 

 which the muscular fibres, during life, consist of a homo- 

 geneous, solid or fluid substance, or of minute particles, con- 

 nected in two directions. To Bowman's opinion, moreover, 

 is opposed the fact, that his assumed "elementary particles," 



Fig. 92. A, a primitive fasciculus, separating transversely into discs, x 350 diara. 

 It exhibits distinct transverse and fainter longitudinal striae. The discs, of which 

 one more highly magnified is seen at B, are granular, and consist of the primitive 

 particles (sarcous elements) of Bowman, or segments of the fibrils according to other 

 authors (after Bowman). 



