THE MUSCULAR SYSTEM. 



225 



Fig. 92. 



This is the opinion entertained by Remak, who thinks a pre-existing 

 division of the muscular cylinder still problematical ; of Briicke, who 

 appears to regard the contents of the muscle-tubes during life as fluid ; 

 of Du Bois-Reymond, and, above all, of Bowman. According to the 

 latter, a division of the muscular fibres into " discs" (Fig. 92) is quite as 

 natural, although not so frequent, as that into fibrils, 

 and that they may be considered as columns composed 

 of such discs, quite as correctly as bundles of fibrils. 

 Were a muscular fibre completely divided in the direc- 

 tion of both the transverse and longitudinal striae, 

 rounded, angular, minute particles would be produced, 

 which may be termed primitive particles, or " sarcous 

 elements," In the fibre, these elementary particles are 

 connected in both directions, the same particles in the 

 one case constituting a "disc," and in the other a seg- 

 ment 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 fre- 

 quently 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 mace- 

 rated 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 longitudinal 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, connected in 

 two directions. To Bowman's opinion, moreover, is opposed the fact 

 that his assumed "elementary particles," except in macerated muscles, 

 where such a thing readily occurs, can only with difficulty be obtained 

 in an isolated form, whilst, according to his view, such a disintegration, 

 in cases where these particles do not cohere firmly, either in a longitu- 

 dinal or transverse direction, would necessarily take place with equal 



FIG. 92. Jl, a primitive fasciculus, separating transversely into discs; magnified 350 

 diameters. 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 (parcous elements) of Bowman, or segments of the fibrils according to other 

 authors (after Bowman). 



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