10 



the inediüd of BiKi.wciiowskY, gaiiyliuncL'lls were scairc, and in I'act 

 1 often looked in \ain for them. It was only in the 'lerve plexus 





tig. 11, 1'' and IB. Ganglioncells from the plexus ciiiaris 

 of the human eye. 



of the corpus eiiiaie that ganglioncells were to he found, of the 

 type tigured in tig. JJ, 12 and J 8. It therefore seems improbable 

 that they should exist in the numbers required for the theory of 

 Inglis Pollock. So from this point of view too renewed research is 

 necessary and especially it will be necessary to \erify the interesting 

 results of the last-named author. 

 Leiden, April 1915. 



Geology. — "How rolcanism inüjht be explained." By Dr. C. G. S. 

 Sandberg. (Communicated by Prof. Dr. C. E. A. VVichmann). 

 (Gommuntcaled in the meeling of April 23, 1915). 



To explain the phenomenon of volcanic eruptions and the mode 

 of their origin, it has long been considered necessary to assume that 

 large cpiantities of sea-water were suddenly brought in contact with 

 incandescent and liquid magma, by means of deep-reaching fissures 

 or crevasses in the crust of the earth. 



The fact that the gaseous volcanic emanations showed some similarity 

 with the constituent elements of sea water and the proximity of 

 the seat of volcanic activity to marine areas, led to our looking 

 for a causal connection between these phenomena. 



