26 Analogy between Vegetables and Animals 



i-eferred to muscular contraction, shall we not be justified in 

 concluding that vegetables, as well as animals, are furnished 

 with muscular organs. Most persons are aware that when 

 the lower part of the stamens of the flower of the berberry 

 {Berberis vulgaris) are touched, however slightly, they in- 

 stantly bend themselves towards the pistil ; in a short time 

 they become relaxed, and resume their natural position. The 

 contractile effect in this case, as far as I have observed, is 

 always much greater than the amount of the cause by which 

 it is produced; and, in experiments, I have witnessed that 

 relaxation will take place at the same time that the mechanical 

 cause which excited the contraction continues to be impressed. 

 Moreover, the stamen of the berberry can be made to contract, 

 even after it is cut from the flower, precisely in the same 

 manner as the heart can be excited to action after it has been 

 removed from the body. In the sensitive plant [or rather, 

 humble plant, Mimosa pudica] we perceive very strong indi- 

 cations of contractility. It is well known that its leaves will 

 collapse on the slightest touch, and fold themselves up. The 

 Dionae^a Muscipula is another striking example of the existence 

 of muscular contractility in plants. The leaves are each ter- 

 minated by two lobes, which are furnished with long spines, 

 and besmeared by a fluid substance which they secrete. As 

 soon as a fly alights upon the lobes they immediately close, 

 and, by squeezing the insect forcibly upon their points, they 

 kill it almost instantaneously. The upper surface of the leaves 

 of the Drosera rotundifolia (common or round-leaved sundew) 

 is covered with a number of small red hairs, on the extremity 

 of each of which is placed a globule of viscid fluid. When 

 an insect comes upon the leaf, the hairs, which are very con- 

 tractile, bend round it on every side, and keep it fast. The 

 viscid globules also serve to detain it; but their chief use seems 

 to be to destroy its life, which, by their excessive acrimony, 

 they speedily accomplish. The two lips of the stigma of the 

 Gloxinm*, before fructification, are seen to open; but, as soon 

 as a particle of pollen falls upon their inner surface, they 

 instantly close. From these examples, and I could adduce 

 many more, it will be perceived that several of the actions of 

 plants are attended with phenomena which can be attributed 



* In which, or in every, species of Gloxink ? The stigma in the genus 

 ikfimulus is also formed of two broad lips, which in warm weather are dis- 

 tended, but promptly collapse on being touched; M. luteus evinces this 

 irritability very conspicuously, in which species it was discovered, and first 

 pointed out to me, by a botanical assistant, Mr. George Woolsey. I have 

 subsequently examined M. moschatus, and other species of this genus 

 which exhibit the same phenomenon, although in a lower degree than 

 M. luteus does. Mi*. David Don informs me that the lips of the stigma 

 in M. glutinosus are eminently sensitive. — .7. D, 



