REMOVAL OF NASAL PITS AMBLYSTOMA EMBRYOS 



45 



text figures 1, 2 and 3 will make evident that there is a pro- 

 gressive enlargement of the venti'icles from the normal through 

 the brains of the unilaterally operated larvae to the bilaterally 

 operated larvae. It is not possible at this time to explain the 

 significance of this difference if any exists. 



