OBSERVATIONS ON THE HISTOLOGY OF STRIPED MUSCLE. 79 



to the above question. He states that he has traced the 

 termiual fibrils of the nerves into direct connection with 

 the intra-nuclear network of the hepatic cells, and the figures 

 he gives seem to place this beyond doubt. This by analogy 

 gives support to the view that the nerve-ending of muscle is 

 connected with the network ; and possibly this is the normal 

 method of termination of nerves in connection with cells. 



Haswell's^ observations are also interesting in connection 

 with this question. He describes a ganglion-cell at the end of 

 each fibre, and occupying the axis of the fibre. This sends out 

 numerous branching processes, which penetrate between the 

 fibrils. He states that the core of the fibre is occupied by 

 granular protoplasmic material, through which runs a network 

 of fine threads, " connected with the fine branches of the nerve- 

 processes of the ganglion-cell, and with the network of the 

 muscle substance.^^ Special branches of nerve-processes also 

 ramify on the surface of the fibre, and probably enter into con- 

 nection with the transverse networks. 



Hence both Macallum^s and Haswell's observations lend 

 support to the view that the network is connected with the 

 nerve-ending. 



Conclusion. 



In reviewing the foregoing observations we are at once met 

 by an apparent contradiction, viz. that in the young muscle- 

 fibre the network does not appear to be connected with the 

 nucleus, whereas the connection is definitely established 

 (Eetzius, Marshall) in the adult fibre. This at first sight is an 

 absolute contradiction : for, on the one hand, it is difficult to 

 conceive that processes originating as outgrowths from the 

 nucleus could exactly hit off and fuse with the already formed 

 network ; on the other hand, it is almost equally inconceivable 

 that the fibres should grow into the nucleus. This apparent 

 contradiction can, I think, be to a great extent explained. 

 Firstly, we must bear in mind that histological difi'erentiation 

 proceeds during its development from without inwards, i. e. 



' Loc. cit. 



