Chap. X.] DmECTION OP INFLECTED TENTACLES. 199 



ficient to affect the outer tentacles, but all those near the two 

 points were directed to them, so that two wheels were formed 

 on the disc of the same leaf; the pedicels of the tentacles 

 forming the spokes, and the glands united in a mass over 

 the phosphate representing the axles. The precision with 

 which each tentacle pointed to the particle was wonderful; 

 80 that in some cases I could detect no deviation from per- 

 fect accuracy. Thus, although 

 the short tentacles in the mid- 

 dle of the disc do not bend 

 when their glands are excited 

 in a direct manner; yet if 

 they receive a motor impulse 

 from a point on one side, they 

 direct themselves to the point 

 equally well vCith the ten- 

 tacles on the borders of the 

 disc. 



In these experiments, some 

 of the short tentacles on the 

 disc, which would have been 

 directed to the centre, had the 

 leaf been immersed in an ex- 

 citing fluid, were now inflected 

 in an exactly opposite direc- 

 tion, viz. towards the circmn- 

 ference. These tentacles, there- 

 fore, had deviated as much as 

 180 from the direction which 

 they would have assumed if 

 their own glands had been stimulated, and which may be con- 

 sidered as the normal one. Between this, the greatest possi- 

 ble and no deviation from the normal direction, every degree 

 could be observed in the tentacles on these several leaves. 

 Notwithstanding the precision with which the tentacles gen- 

 erally were directed, those near the circumference of one leaf 

 were not accurately directed towards some phosphate of lime 

 at a rather distant point on the opposite side of the disc. It 

 appeared as if the motor impulse in passing transversely 

 across nearly the whole width of the disc had departed 

 somewhat from a true course. This accords with what we 



Fig. 10. 

 (Drosera rotundifolia.) 

 Leaf (enlarged) with the tenta- 

 cles inflected over a bit of meat 

 placed on one side of the disc. 



