NEUROHUMORS 57 



a finely variegated background by a pattern of finer 

 texture (Fig. 40). Lipohumors are represented by the 

 concentrating and the dispersing neurohumors of Fun- 

 dulus and of Ameiurus, and by the concentrating neuro- 

 humor in Mustelus. Thus the two main groups of 

 neurohumors with their numerous representatives prom- 

 ise a rich field for functional investigation. 



