518 



owing to the different refractive index of the water, are seen 

 far more clearly than on those into which styrax has penetrated^ 

 and in which the chromatophores are utterly spoilt. 



It remains to be proved if this method of preserving the 

 chromatophores is a permanent one or not. The slide, when, 

 exhibited, had been mounted about four months, and up to the 

 time of publishing this note I have not observed any change in 

 the frustules that contained water when first mounted. 



Journ. (^aekell Microscopical Club, 8er. 2, Vol. XL, iVo. 71, November iyi2. 



