Chap. I.] 



STRUCTURE OP THE LEAVES. 



3 



ing 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, but this was not the case in the one here figured. 

 The whole upper surface is covered with gland-bearing 



Fig. 1. 



(Drosera rotundifolut.) 



Leaf viewed from above ; enlarged four times. 



filaments, or tentacles, as I shall call them, from their man- 

 ner of acting. The glands were counted on thirty-one leaves, 

 but many of these were of unusually large size, and the aver- 

 age number was 192; the greatest number being 260, and 

 the least 130. The glands are each surrounded by large drops 

 of extremely viscid secretion, which, glittering in the sun, 

 have given rise to the plant's poetical name of the sun-dew. 



' The drawlnjjs of Drosera and 

 Dionaea, given In this work, were 

 made for me by my son, George 

 Darwin; those of Aldrovanda, 

 and of the several species of 

 o 



Utrlcularla, by my son Francis. 



They have been excellently re- 



pro(niced on wood by Mr. Cooper, 

 188 Strand. 



