Plants That Feed on Insects. 29 



vegetable-feeding animals, as is only too well known, possess 

 a similar power of extracting nourishment from such articles. 

 Though properly an insectivorous plant, but as pollen, as well 

 as the seeds and leaves of surrounding plants, cannot fail to 

 be often or occasionally blown upon the glands of Drosera, 

 yet it must be credited with being to a certain extent a vege- 

 table feeder. 



That a plant and an animal should secrete the same, or 

 nearly the same, complex digestive fluid, adapted for a simi- 

 lar purpose, is a wonderful fact in physiology, but not more 

 remarkable than the movements of a tentacle consequent 

 upon an impulse received from its own gland, the movement 

 at the bending place of the tentacle being always towards the 

 centre of the leaf, and so it is with all the tentacles when 

 their glands are excited by immersion in a suitable fluid. 

 The short tentacles in the middle part of the disc, however, 

 must be excepted, as these do not bend at all when thus 

 excited. But when the motor impulse comes from one side 

 of the disc, the surrounding tentacles, and even the short 

 ones in the middle of the disc, all bend with precision 

 towards the point of excitement, no matter where it may be 

 located. This is in every way a remarkable phenomenon, 

 for the leaf appears as if endowed with animal sense and 

 intelligence. It is all the more remarkable when the motor 

 impulse strikes the base of a tentacle obliquely to its flat- 

 tened surface, for then the contraction of the cells must be 

 restricted to one, two or a very few rows at one end, and 

 different sides of the surrounding tentacles must be acted on 

 that all may bend with precision to the point of excitement. 

 The motor impulse, as it spreads from one or more glands 

 across the disc, enters the bases of the surrounding tentacles, 

 and instantly acts on the bending place, but does not first 

 proceed up the tentacles to the glands, causing them to 

 reflect back an impulse to their bases, although some influ- 

 ence is sent up to the glands, whereby their secretion is 

 soon increased and rendered acid. The glands, being thus 



