Arr<nif/<'int'i>f in 



Area 



127 



Interrudntri/ Plexus and Association Fibres. 



The great fibre wealth <>f the whole radiary zone is perhaps the most noteworthy feature 

 of this type of cortex. Not only are the delicate fibrils constituting the interradiary plexus 

 proper numerous, but there is an extraordinary abundance of long association fibres which 

 cross the radiations and interradiary spaces in every direction. These fibres have a preference 

 for that part of the radiary zone which immediately adjoins the white substance, but at the 

 same time they are to be found close up under the line of Baillargcr, and even within 

 that line, and as I have mentioned already the upper part of the radiary zone has not that 

 pallid appearance which was observed in the calcarme region. 



FIG. 12. Radiary zone in the occipital or visuo-psychic cortex. x 4 ^. 



The features of this cortex are best brought out by comparing it with that of surrounding parts, for instance the 

 common temporal cortex (Plate XIII, fig. 3). Then the large medullated fibres, which are undoubtedly of great 

 importance, and the general fibre richness will be noticed. 



Comparing the calibre of these large association fibres with that of the fibres in the 

 calcarine cortex, which we made special reference to under the name of the optic fibres of 

 Ramdn y Cajal, we find that the latter have a slight advantage in point of size. 



