388 THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



processes, it is so much the more frequently cut off, the greater the 

 thickness of the whole hemisphere, and the farther the ganglionic 

 extremity of the projection-fibre lies from the cortex. Perhaps the 

 greater friability which characterizes the axis-cylinder processes also 

 prevents the frequent observation of this process in preparations made 

 by teazing out. 



The nerve corpuscles of the cortex of the cerebrum are 

 destitute of a cell wall, and Max Schultze, in chapter iii. of this 

 work, has described their protoplasm as presenting a granular 

 fibrous character. The younger the individual, and the more 

 closely approximating the natural state is that in which the 

 brain is examined, the more rarely does the protoplasm of the 

 pyramids of the fusiform bodies to be mentioned hereafter, 

 as well as of the irregularly shaped bodies of the first layer, 

 contain round or oval nuclei; but, on the contrary, angular 

 nuclei of the same shape as the protoplasm, i.e. of pyramidal 

 or fusiform shape, running out into points (fig. 235, a b d\ 

 The angles and points of the nucleus are frequently produced 

 into the processes of the cells, which is opposed to the view 

 of Arndt, that these are vesicular nuclei that have been 

 squeezed by the masses of protoplasm in accordance with their 

 shape. If we combine the statements made by Beale, respect- 

 ing the existence of a denser layer of protoplasm immediately 

 surrounding the nucleus, with the direction of the proto- 

 plasmatic fibrillse, described by Schultze as concentrically 

 converging towards the processes, the idea of small similarly 

 formed dense pyramids and spindles in the interior of a 

 pyramidal or fusiform cell is powerfully supported. This 

 angular included body would then be prolonged as a portion 

 of the protoplasm into the protoplasm of the processes. 



Quite independently of any interpretation of the appearances seen, 

 I have convinced myself of the wide distribution of angular nuclei 

 resembling the masses of protoplasm in form throughout the whole 

 nervous centres, and Herr Ernst Fleischl has kindly furnished me 

 with sections of the spinal cord of the Fish, containing nuclear struc- 

 tures similar to those I have observed in the spinal cord of Man. 



The nucleoli are circular, lustrous, and in carmine prepara- 



