76 



THE PRESERVATION OF PLANTS AS FOSSILS. 



[CH. 



transparent film often shows very clearly the outlines of the 

 epidermal cell and the form of the stomata. Such treatment 

 has been found useful in many cases as an aid to determination \ 



Prof. Zeiller informs me that he has found it particularly satis- 

 factory in the case of cycadean leaves. 



It is sometimes possible to detach the thin lamina repre- 

 1 Bornemann (56), Schenk (67), Zeiller (82). 



