576 SCIENCE PROGRESS 



Researches on Irritability of Plants. By Jagadis Chunder Bose, M.A., 

 D.Sc, C.S.I., Professor, Presidency College, Calcutta. [Pp. xxiv + 376; 

 190 figures.] (London : Longmans, Green & Co., 191 3. Price js. 6d. net) 



IT is with mixed feelings that one takes up a new volume by Professor Bose. 

 One expects to be filled with appreciation of extremely delicate experimentation 

 and of apparatus most ingeniously devised. On the other hand, one is sure to 

 be repelled by the curious standpoint from which the author views living 

 organisms, a position quite impossible of acceptance by physiologists generally. 

 In the several volumes which the author has already published we always find 

 insistence on the view that the internal energy of the plant, such as is exhibited in 

 movements in response to stimuli, is derived from without by the absorption 

 of "stimuli " received from the environment in the form of light, heat, and even 

 mechanical energy. The author never explains how the energy obtained from, 

 say, wind and heat is stored up in the plant, nor, on the other hand, does he 

 explain why he rejects the ordinary view that the energy exhibited by the plant 

 is derived from the oxidation of organic material elaborated by the leaves. 

 Prof. Bose's almost bizarre attitude towards living organisms is perhaps to be 

 explained by the fact that he entered physiology from physics. It is, however, 

 particularly unfortunate, for it is, no doubt, mainly responsible for the neglect 

 of his work by biologists generally. 



Fortunately, in the present work theory is kept in the background, though 

 the author speaks in one place of a portion of a stimulus bringing about an 

 immediate response, while another portion is stored up and causes response later, 

 or else increases the tonic condition of the plant ! Leaving theory on one side, 

 we find a large amount of valuable work. As was to be expected, he describes 

 some very ingenious apparatus, his Resonant Recorder and Oscillating Recorder 

 being particularly worthy of mention. There is very great difficulty in obtaining 

 in the ordinary way direct records of the movements of such leaves as those of 

 Mimosa and Biophytum, for the force producing the movements is very slight, 

 so that the mere friction of the style on a smoked plate causes distortion, or 

 even complete arrest of the movement. In these two instruments the difficulty 

 is completely surmounted by making the contact between the smoked plate and 

 writing style intermittent. By this means the friction is greatly reduced, the 

 record appearing as a number of dots, and as contact occurs at regular intervals 

 no other time-record is necessary. By means of the first of these instruments 

 Prof. Bose has been able to show that the "latent period in Mimosa is o"i sec, 

 and that the rate of transmission of the stimulus in the petiole may reach 30 mm. 

 per sec. ; but is markedly retarded, and finally abolished by lowering the tem- 

 perature." These results are quite incompatible with the commonly received 

 hydro-mechanical theory of the transmission of the stimulus. They indicate 

 that the transmission is a protoplasmic one and of a nature similar to that in 

 animal nerve. In fact, very strong evidence is brought forward in support 

 of a close similarity between Mimosa and a nerve-muscle preparation ; for the 

 pulverius appears to behave like a contracting muscle in doing more work as 

 the load is increased. Besides these important results there are a large number 

 of valuable observations on multiple response to a single stimulus (the existence 

 of this type of response the reviewer can confirm from his own observations), 

 on polar effects of electrical currents, on the contrasted effect of anode and 

 kathode, and on many other phenomena exhibited by motile organs. The book 

 is certainly one that cannot be neglected by workers in the fields of either 



