10 General Remarks on Cortical Fibre and Cell Arrangement [CHAP. 



short paper by Professor Vogt, giving the aims of his further researches and containing some 

 excellent microphotographic illustrations 1 of certain types of cell-lamination, for the prepara- 

 tion of which, Brodmann, a worker in the same laboratory, is given credit, and it appears that 

 Brodmann is taking over, or at any rate sharing, the cytological work in this undertaking. 



In addition to those mentioned, advantage has been taken of the pathological and 

 histological investigations on cortical structure of the following; Bruckner, Kb'lliker, Edinger, 

 Obersteiner. Goodall and MacLulich, Tuczek, Zacher, Mott, and Schaffer, all of whom have 

 paid attention to the medullated nerve fibres; and of Apathy, Bethe, Donaggio, van Gehuchten, 

 Goldscheider and Flatau, Held, Hoche, Lenhosse'k, Marinesco, and Nissl, who rank high among 

 those who have advanced our knowledge of neuro-cytology. 



A GENERAL CONSIDERATION OF THE ARRANGEMENT OF MEDULLATED 

 NERVE FIBRES IN THE CEREBRAL CORTEX, WITH SPECIAL REFERENCE 

 TO TERMINOLOGY. 



Since the nomenclature applied to the fibre constituents of the cortex promises to 

 become as bewildering as the various classifications applied to nerve cell-lamination, it is 

 necessary, in approaching a discussion on the arrangement of these fibres, to have a clear 

 understanding of the terminology employed by previous workers. 



Outermost Fibreless Layer. 



In sections of the cortex stained for the display of nerve fibres, a shallow, pale, super- 

 ficial layer, forming a delicate margin, can be invariably seen. In this a few isolated fibres 

 of extremely fine calibre, running in all directions, but chiefly vertically or obliquely, are 

 generally recognisable ; Ramon y Cajal suggests that they are collaterals from larger fibres 

 in subjacent layers. The layer owes its pallid appearance to the fact that it is mainly 

 composed of glia cells, and as it possesses little importance, in so far as nerve fibres are 

 concerned, it can be dismissed without further remark. 



Zonal Layer. 



Synonyms Tangentiale Randzone, Zonal Fibres, Tangential Band, Plexus Externus, 

 Plexiform Layer, Deckschicht, Lamina Medullaris Externa. These are some of the names 

 which have been applied to a readily-recognised layer of nerve fibres, which is situated 

 immediately beneath the outermost fibreless layer, and envelops the convolutions in bandlike 

 fashion. Following Kaes' lead, I shall refer to this band, hereafter, as the zonal layer, 

 and discard the designation " tangential band " commonly used by writers in this country. 

 That the latter name is expressive, there is no denying, but at the same time the term 

 " tangential " has been applied to the so-called association fibres lying in deeper planes of 

 the cortex, and to avoid confusion it is preferable to dispense with its use altogether. I 



1 These are low power views apparently made with a projection apparatus. They illustrate a few different types 

 of cell-lamination and seem to have been published in justification of the extension of the work. 



