182 E. A. Schäfer, 



The same remark would not apply if the inter-reticular substance 

 of the leg-muscle (assuming that substance to be continuous throughout 

 the fibre) were regarded as the contractile part, because this substance 

 certainly corresponds with the obviously contractile „fibrils" of the 

 wing-muscles, and it might be alleged to be of the same nature, only 

 not naturally divided up into „fibrils." This view, which was, in 

 fact, the position taken by me in 1873, does not appear to have 

 been adopted by any of the more recent advocates of the reticulum - 

 theory, who have, in investigating the structure of muscle, been mostly 

 by their own showing *) directly influenced by the views regarding 

 the structure of protoplasm which have been of late years so zealously 

 promulgated by Carnoy and others belonging to the Louvain School. 

 According to these views all protoplasm is essentially composed of a 

 contractile reticulum which contains in its meshes a passive enchylema. 

 Starting from this basis, it is a simple matter to argue that since 

 muscle is derived from cell-protoplasm and possesses so markedly the 

 contractile function, it should therefore exhibit a well-marked reticulum, 

 which must, of course, by the terms of the original assumption, be the 

 contractile part of the fibre. And it is equally easy to carry the 

 analogy further and to argue that since the enchylema of protoplasm 

 is a continuous substance occupying the meshes of the reticulum, there- 

 fore the inter-reticular substance must be of the same homogeneous 

 nature as that enchylema. 



Does protoplasm contain a contractile reticulum? 



It may be worth while, then, as bearing upon the present question, 

 to digress for a moment and examine the evidence upon which these 

 views, which regard distinction into the reticulum and enchylema as 

 essential to protoplasm, rest. It may be at once admitted that many, 

 perhaps most cells exhibit a structure which may be thus described. 

 The point to be determined, however, is not whether it exists in any 

 cells or even whether it is widely distributed, but whether it is 



] ) Van Gebuchten, Dedication of first article. 



Melland, Quarterly Journal of Micr. Science 1885. p. 371. 

 Marshall, Quarterly Journal of Micr. Science 1887. p. 75. 



