31? 



Lacerta agilis 



Small 



\ Varanus salvator 



Reguliis crist. 

 (after Brandis) 



Anser canadensis 

 (after Brandis) 



Columba dom. 



Mus musculus 



Mus musculus 



Tragiilus javan. 



Struthio camelus 

 (sec. Streeter) 



Dasyprocta agouti 



Lepus cuniculus 



Hippotragus niger 



Elephas indicus. 



Fig. 2. Relation between grey (black) and white (white) matter in the cervical 

 cord of small and large representants of the same orders. (The sections 

 are drawn in the same size in order to show better the relative enlarge- 

 ment of white substance). 



