20 DROSERA ROTUNDIFOLIA. Chap. H. 



exterior tentacles, near their bases, and does not (as 

 will hereafter be proved) first travel up the j)edicels to 

 the glands, to be then reflected back to the bending 

 place. Nevertheless, some influence does travel up to 

 the glands, causing them to secrete more copiously, 

 and the secretion to become acid. This latter fact 

 is, I believe, quite new in the physiology of plants ; 

 it has indeed only recently been established that in 

 the animal kingdom an influence can be transmitted 

 along the nerves to glands, modifying their power of 

 secretion, independently of the state of the blood- 

 vessels. 



Th6 Inflection of the Exterior Tentacles from the Glands 

 of the Disc heing excited hy Bepeated Touches, or hj 

 Objects left in Contact with them. 



The central glands of a leaf were irritated with a 

 small stiff camel-hair brush, and in 70 m. (minutes) 

 several of the outer tentacles were inflected ; in 5 hrs. 

 (hours) all the sub-marginal tentacles were inflected ; 

 next morning after an interval of about 22 hrs. they were 

 fully re-expanded. In all the following cases the period 

 is reckoned from the time of first irritation. Another 

 leaf treated in the same manner had a few tentacles 

 inflected in 20 m. ; in 4 hrs. all the submarginal and 

 some of the extreme marginal tentacles, as well as the- 

 edge of the leaf itself, were inflected ; in 17 hrs. they 

 had recovered their proper, expanded position. I then 

 put a dead fly in the centre of the last-mentioned leaf, 

 and next morning .it was closely clasped; five days 

 afterwards the leaf re-expanded, and the tentacles, 

 with their glands surrounded by secretion, were ready 

 to act again. 



Particles of meat, dead flies, bits of paper, wood, 

 dried moss, sponge, cinders, glass, &c., were repeatedly 



