842 
SPONTANEOUS MOVEMENTS IN PLANTS. 
stamens. The pollen is thus thrown on to the head or body 
of the insect, which carries it away to the next flower it visits, 
and leaves some of it on the stigma, and thus cross-fertilisation 
instead of self-fertilisation is secured. Similar motion of the 
stamens towards the pistil, but spontaneous, takes place in 
the case of the London Pride, and other species of Saxifraga. 
Elasticity is, indeed, a common property of organised 
tissue, though it is not often developed to so evident an ex¬ 
tent. In the “ touch-me-not,” or Impatiens , we have a fa¬ 
miliar instance in the seed-vessel, which, if touched when 
nearly ripe, suddenly coils back, throwing the seeds to a con¬ 
siderable distance. The “ squirting cucumber ” (Momordica 
Elaterium) marks the period of ripeness by the fruit sepa¬ 
rating from its stalk, and expelling the seeds and juice with 
great violence. Mr. Thomas Meehan described a remarkable 
instance of elasticity at a recent meeting of the Academy of 
Natural Sciences of Philadelphia. The seeds—or, as would 
appear from his description, more correctly the embryos of 
the seeds—of the American te witch-hazel ” (Hamamelis vir- 
ginica ) are thrown out with such force as to strike people 
violently in the face who pass through the woods. Collecting 
a number of the capsules, and laying them on the floor, he 
found the seeds or embryos were thrown out generally to the 
distance of four or six feet, and in one instance as much as 
twelve feet. 
Many of the instances of spontaneous motion or irrita¬ 
bility we have now recorded may doubtless be explained by 
the application of known physical laws. With others this is 
not so easy ; and it is but reasoning in a circle to say that, 
because the organisms which manifest them belong to the 
vegetable kingdom, therefore the phenomena cannot be the 
result of a sentient force acting upon, and independent of, 
matter. Darwin has described how certain movements of 
the tendrils of climbing plants would be termed instinctive if 
they were observed in animals. The rapid rotatory motion of 
the zoospores of the lower Algae is absolutely undistinguish- 
able from that of certain undoubted lowly organised forms of 
animal life. It is very difficult to distinguish between the 
movement of a shoot of a climber performing its circles in 
the air in search of a support, and that of the tentacula of a 
coral-polyp in search of food. The mode in wffiich the 
Venus's Fly-trap seizes and encages its prey is very like that 
adopted by a sea-anemone. Every fresh addition to our 
knowledge seems to confirm us in the view that it is unwise 
to dogmatise by laying down too rigid generalities, and 
absolutely to deny certain functions to whole classes of 
