ANIMAL AND VEGETABLE 189 



CHAPTER XIII 

 NISSL'S GRANULES 



THAT many of the nerve cells, if not all of them, contain 

 organically combined iron, as suggested by Macallum, I do 

 not doubt, but the weak link which has hitherto existed 

 in my chain of reasoning has been the manner in which 

 Nissl's granules so-called have been shown, in physio- 

 logical and histological works, to be distributed in the cell 

 contents. 



As will be seen from Figs. 109, 110 (taken from Schafer), 

 they appear as masses, and this is not quite consistent 

 with the theory that neuro-electricity is generated by the 

 association of iron with oxygen in the protoplasm. One 

 would expect to find iron in the form of minute particles 

 arranged in the cell contents in a well-defined manner ; 

 a manner which, if it could be seen with a sufficiently high 

 power, would make it clear how electrical attraction and 

 repulsion as well as generation are brought about. In 

 health not only does the nucleus occupy a central position 

 in the cell, but the nucleolus is more or less centrally 

 situated in the nucleus, and this phenomenon, as well as 

 that of amoeboid movement, would seem to have its origin 

 in electrical activities and to be in accordance with the 

 experiments of Ampere. 



With iron in the shape of irregular masses it is difficult 

 to see how this harmonious result is arrived at, no matter 

 how convinced we may be that it is so. 



The illustrations to which jl have referred were based 



