240 EESE ARCHES ON SECONDARY ELECTROMOTIVE 



either end or commence in the tendinous intersection. Hence the 

 stimulus imparted by the nerve would not start from the neigh- 

 bourhood of the equator of the pair of muscles, i.e. from the region 

 of the intersection, but each half being functionally a muscle of 

 itself would have its own equator. 



It would be contrary to all analogy if the motor end plates were 

 especially crowded together in the vicinity of the intersections ; this 

 would be much more likely to be the case in the neighbourhood of 

 the equator of each individual half of the muscle, with the exception 

 of the long fibres of the semimembranosus. Instead of comparing 

 the positive polarisation in both halves of the muscle, du Bois- 

 Reymond ought to have investigated each quarter of the muscle for 

 comparison. In the first and third quarters, counting from above, 

 the ascending positive polarisation ought to have proved strongest, 

 in the second and fourth the descending, if the experimental 

 evidence was intended to support the suggestion of a connection 

 between functional direction and positive polarisation. 



For the rest in Sect. 21 of his paper (No. VI), du Bois-Reymond 

 makes no further statement about the muscles with which the 

 researches were actually conducted, when he says, ' In regular 

 monomerous muscles (i. e. those consisting of longitudinal fibres only) 

 positive polarisation is stronger in the direction from the equator 

 towards the ends, than in the opposite direction.' No experiments 

 however on monomerous muscles are contained in the whole treatise, 

 but only those already mentioned with the rectus internus and semi- 

 membranosus, which are pre-eminently 'pleiomerous' muscles, i.e. 

 such as have fibres commencing and terminating within their limits. 

 Moreover, had du Bois-Reymond repeated his experiments with 

 monomerous muscles, he would have found the true condition to be 

 the reverse of his statement with regard to them, viz. that with 

 stimulating currents of relatively equal strength (and corresponding 

 density) and of the same short closing time (0-32") he would have 

 found positive polarisation in the half of the muscle next the 

 stimulating anode, none or weak negative polarisation in the half 

 next the stimulating kathode, and through which therefore the 

 current flowed in the direction from the equator towards the end. 

 Had du Bois-Reymond instituted such experiments as these, he 

 would at once have recognised that the muscle is not polarised in 

 the same direction, in the whole intrapolar tract (see below). 



In du Bois-Reymond's speculations as to the connection between 

 positive polarisation of muscle and the direction in which the 



