Page:Researches on Irritability of Plants.djvu/24

 

RESEARCHES ON IRRITABILITY OF PLANTS

CHAPTER I

PLANT SCRIPTS

Action of environment on plant—Revelation of internal condition by character of response—Problems to be solved—Electrical response—Mechanical response—Motile organ in Mimosa pudica—Response in plant and animal—Different phases of the responsive movement—Graphic record—Determination of absolute movement of leaf and its time-relations—Characteristic effects of different agencies on the response-curve—Specific difficulties in recording plant-response.

In strong contrast to the energetic animal, with its various reflex movements and pulsating organs, stands the plant in its apparent placidity and immobility. Yet that same environment, which with its changing influences so strikingly affects the animal, is playing upon it also. Storm and sunshine, the warmth of summer and the frost of winter, drought and rain, all these and many more come and go about it. What coercion do they exercise upon it? What subtle impress do they leave behind? That they, in their totality, do leave the plant better or worse for their occurrence, we know. It is evident that internal changes are effected by their agency which are entirely beyond our visual scrutiny. Would it be possible to trace this general action of the environment into some detail, and then follow out the question of its particular effects upon the vegetal organism? Is there any means by which we might find out