1914] on Plant-Autographs and their Revelations 173 



animal are not to be found in the plant ; for example, it is urged 

 that, unlike the animal, the majority of plants ar^ insensitive to a 

 blow, exhibiting no shuddering twitch, either mechanical or elec- 

 trical ; and that even in the sensitive Mimosa, an irritation does not 

 cause an excitatory impulse, but a mere hydraulic disturbance. The 

 pendulum then swings from these hasty assumptions to the diametric- 

 ally opposite extreme. Under these circumstances the clear path 

 is that which leads us away from theory and disputations to find 

 the thread of fact. We must, therefore, abandon all our pre- 

 conceptions, and put our questions direct, insisting that the only 

 evidence which can be accepted is that which bears the plant's own 

 signature. 



How are we to know what unseen changes take place within the 

 plant ? If it be excited or depressed under some special circum- 

 stance, how are we, on the outside, to be made aware of it ? The 

 only conceivable way would be, if that were possible, to detect and 

 measure the actual response of the organism to a definite testing 

 blow. When an animal receives an external shock, it may answer 

 in various ways ; if it has voice, by a cry ; if it is dumb, by the 

 movement of its limbs. The external shock is the stimulus; the 

 :inswer of the organism is the response. If we can find out in the 

 plant the relation between the stimulus and response, we shall be 

 ible to determine its state of vitality at the moment. In an excit- 

 able condition, the feeblest stimulus will evoke an extraordinarily 

 large response ; in a depressed state even a strong stimulus evokes 

 only a feeble response ; and, lastly, when death has overcome life, 

 there is an abrupt end of the power to answer at all. 



We might, therefore, have detected the internal condition of the 

 plant, if we could have made it write down its responses. In order 

 to succeed in this, we have, first, to discover some compulsive force 

 which will make the plant give an answering signal ; secondly, we 

 liave to supply the wherewithal for an automatic conversion of these 

 signals into an intelligent script ; and, last of all, we have ourselves 

 to learn the nature of the hieroglyphic. 



Response of Plant and Animal. 



In answering the question whether there is a fundamental unity 

 in the response of plant and animal, we have first to find out whether 

 sensitiveness is characteristic of only a few plants or whether all 

 olants and every organ of every plant is sensitive. Then we have to 

 Jevise apparatus by which visible or invisible reactions are detected 

 md recorded. Having succeeded in this, we have next to survey 

 the characteristic reactions in the animal, and find out whether 

 phenomena corresponding to these may also be discovered in the 

 plant. 



