DROSERA ROTUNDIFOLIA. 



Chap. I. 



secoiiflly, the power possessed by the leaves of render- 

 ing]^ soluble or digesting nitrogenous substances, and 

 of ai'terwards absorbing them; thirdly, the changes 

 which take phice within the cells of the tentacles, when 

 the glands are excited in various ways. . 



It is necessary, in the first place, to describe briefly 

 tlie plant. It bears from two or three to five or six 

 loaves, generally extended more or less horizontally, 

 but sometimes standing vertically upwards. The shape 

 and general appearance 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 broader than long. 



.«fe^£&Mi*r 



Fig. 2. 



(Drosera rotundi folia.') 



Old leaf viewed laterally ; enlarged about five times. 



l)iit tliis was not the case in the one here figured. 

 The whole upper surface is covered with gland-bearing 

 lilament.s, or tentacles, as I shall call them, from their 

 ni a liner of acting. The glands were counted on thirty- 

 on(,' leaves, but many of these were of unusually large 

 size, and the average number was 192; the greatest 

 number being 2(30, and the least 130. The glands are 

 each surrounded by large drops of extremely viscid 

 s<M.Totion, which, glittering in the sun, have given rise 

 lo the plant's poetical name of the sun-dew. 



The tcntadcs on tlic central part of the leaf or disc are 

 sliort and stand ni)nVdit, and tlieir ixdiccls are green. Towards 

 the mari,'iu tliey become longer and longer and more inclined 



