514 THE BRAIN OF MAMMALS, BY TH. MEYNERT. 



become elongated and spindle-shaped, and change into the 

 connective-tissue fibres of the innermost layer of the pia ma- 

 ter. This connective-tissue investment contains at the same 

 time the thickened triangular points of attachment of the 

 radiating supporting trabeculse, resembling those seen in the 

 retina, which have been described by E. Schulze, Bergmann, 

 and Deiters, and which Obersteiner followed to their connection 

 with the reticular stroma, as far as to the inner margin of the 

 pure grey layers, under most favourable conditions of isolation, 

 in the cortex of a cerebellum that appeared as though it had 

 been pencilled out, in consequence of an atrophic process of 

 encephalitis. 



The remaining separable layers are (1) the pure grey layer, 

 which is the most external ; (2) the middle thin layer of large 

 cells of Purkinje ; and (3) the internal greyish-red or granule 

 layer (fig. 259, la, 16, 2, 3). The external layer contains a 

 large proportion of a reticulo-molecular matrix, precisely 

 similar to the connective- tissue matrix of the cortex cerebri, 

 which Stilling alone regards as a felt composed of the finest 

 ramifications of the ganglion-cell processes. In addition to 

 what appear to be free nuclei of the connective tissue, small 

 triangular (pastille-shaped) and fusiform nerve corpuscles are 

 imbedded, measuring from 6 to 10 /u. On account of the 

 fluidity of their protoplasm, it is often more difficult than in 

 the cerebral cortex to satisfy one's self of their being really 

 nerve corpuscles. 



At the inner margin of this layer, around the furrow between 

 every pair of convolutions, these small elements are elongated 

 and fusiform, and are parallel and in connection with a layer of 

 transverse finely varicose nerve tubes (fig. 259, 16), which 

 certainly have the appearance of being " fibrse proprise " of the 

 cerebellar cortex. We cannot, however, regard them as such 

 with absolute certainty, because, as we shall show hereafter, the 

 processes of the adjoining large cells also extend transversely 

 around the sulci, and might produce the appearances in 

 question, though if so they would be undoubtedly connected 

 with the processes of the small cells. 



The middle layer of the cerebellar cortex contains the large 

 corpuscles of Purkinje, arranged in a single layer (fig. 259, 2). 



