230 DROSERA ROTUNDIFOLIA. CHAP. X. 



It is probable that they were killed so instantly that 

 they were not able to transmit any motor impulse ; for 

 in six observed cases (in two of which however the 

 gland was quite pinched off) the protoplasm within 

 the cells of the tentacles did not become aggregated ; 

 whereas in some adjoining tentacles, which were 

 inflected from having been roughly touched by the 

 pincers, it was well aggregated. In like manner the 

 protoplasm does not become aggregated when a leaf is 

 instantly killed by being dipped into boiling water. 

 On the other hand, in several cases in which tentacles 

 became inflected after their glands had been cut off 

 with sharp scissors, a distinct though moderate degree 

 of aggregation supervened. 



The pedicels of the tentacles were roughly and re- 

 peatedly rubbed ; raw meat or other exciting sub- 

 stances were placed on them, both on the upper 

 surface near the base and elsewhere, but no dis- 

 tinct movement ensued. Some bits of meat, after 

 being left for a considerable time on the pedicels, 

 were pushed upwards, so as just to touch the glands, 

 and in a minute the tentacles began to bend. I 

 believe that the blade of the leaf is not sensitive to 

 any stimulant. I drove the point of a lancet through 

 the blades of several leaves, and a needle three or four 

 times through nineteen leaves : in the former case 

 no movement ensued ; but about a dozen of the leaves 

 which were repeatedly pricked had a few tentacles 

 irregularly inflected. As, however, their backs had 

 to be supported during the operation, some of the 

 outer glands, as well as those on the disc, may have 

 been touched ; and this perhaps sufficed to cause the 

 Blight degree of movement observed. Nitschke* saya 



Bot. Zeitung,' I860, p. 234. 



