Cuar. I.) STRUCTURE OF THE LEAVES. 3 
the leaves of rendering soluble or digesting nitrogenous 
substances, and of afterwards absorbing them ; thirdly, the 
changes which take place within the cells of the tentacles, 
when the glands are excited in various ways. 
It is necessary, in the first place, to describe briefly the 
Fi L" 
(Drosera rotundifolia.) 
Leaf viewed from above ; enlarged four times. 
plant. It bears from two or three to five or sıx leaves, 
generally extended more or less horizontally, but sometimes 
standing vertically upwards. The shape and general ap- 
pearance of a leaf is shown, as seen from above, in fig. 1, and 
as seen laterally, in fig. 2. The leaves are commonly a little 
* The drawings of Drosera and several species of Utricularia, by my 
Dionza, given in this work, were son Francis. They have been ex- 
made for me by my son, George Dar- cellently reproduced on wood by Mr. 
win; those of Aldrovanda, and of the Cooper, 188 Strand. 
B 2 
