LIKE IN PLANTS. 

 Plant Besponae as a Means of Physiological 

 Investigation. By Jagadis Chunder Bose, 

 M.A., D.Sc. Professor, Presidency College, 

 Calcutta. New York: Longmans, Green 

 & Co. $7. 



Except to those who are acquainted with 

 the previous work of this author, the pres- 

 ent treatise may come as a surprise. It is 

 a substantial octavo volume of more than 

 TOO pages, devoted to the elucidation and 

 illustration of a single thesis. Although this?. 

 the3is is here given in many forms and 

 stated in connection with numerous associ- 

 ated topics, it is essentially simple in its 

 outline. It is this: the plant is a machine; 

 its movements in response to external stim- 

 uli, though apparently various, are ulti- 

 mately reducible to a fundamental unity of 

 reaction. But the movements here referred 

 to are not alone the obvious movements 

 which the eye readily sees, as in the case 

 of the sensitive plant and in that of the 

 twiners. Everybody knows to-day that all 

 young parts of plants possess a limited 

 power of movement in response to certain 

 external stimuli, but to this interesting 

 chapter in the life-history of plants Pro- 

 fessor Bose adds others which are of 

 even greater interest. In general, it may 

 be said that, by means of ingenious deli- 

 cate instruments which exaggerate the 

 slightest motions at any spot, he has been 

 able to demonstrate that even the oldest 

 tissues of a plant, so long as they are liv- 

 ing, are capable of responding in a marked 

 degree to certain external stimuli. By the 

 employment of a beam of light reflected 

 from a mirror attached to a multiplying 

 lever, and falling on a recording drum cov- 

 ered with photographic paper or film, he 

 records the amplitude of the very minutest 

 movements of these responses. Now It so 

 happens that many of these responses are 

 exceedingly complex and exhibit confused 

 effects, due to internal energy and external 

 stimulus respectively. Professor Bose be- 

 lieves that he has been able to disentangle 

 these complex phenomena of combined ac- 

 tion. After this disentangling and exact 

 discrimination have been effected, he ar- 

 rives at the conclusion that "there is no 

 physiological response given by the most 

 highly organized animal tissue that Is not 

 with in the plant." 

 A special feature distinguishing this 

 treatise from many of its class is the pre- 

 sentation, at the end of every chapter, of 

 a summary which gi'ves in a few short sen- 



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fences the substance of the chapter. Such 

 synopses are often found in French 

 treatises and are most acceptable, not only 

 to the student, but to the casual reader. 



The treatise considers, first, simple re- 

 sponse, and deals with the universality of 

 sensitiveness in plants. This is naturally 

 followed by a consideration of the modifica- 

 tion of response under various conditions. 

 Here are studied such matters as fatigue 

 in plants, the effect of anaesthetics, and the 

 death-spasm in plants. Next comes a part 

 devoted to excitability and conductivity, to 

 reversal of normal polar effects in living 

 tissues, to electrotonus, and the latent and 

 "refractory" period. Under multiple and 

 autonomous response the author gathers 

 together the results of his studies on tem- 

 perature and rhythmic responses in plants, 

 Introductory to the larger subject of the 

 different tropisms. But, before taking these 

 up, he intercalates two chapters of pro- 

 found interest, namely, (1) the Ascent of 

 Sap, and (2) Growth. His discussion of the 

 former topic is not wholly satisfactory, but 

 it is extremely suggestive. After the trop- 

 isms are examined in most of their rela- 

 tions, he ventures on a general survey of 

 the whole matter, in the course of which 

 he has something to say about variation as 

 induced by external forces that throws 

 light on his views of Darwinism. 



From the foregoing, it will be seen that 

 no summary of the work can be given which 

 does not take up all of the author's own 

 summaries and his concluding part (IX.) 

 as well. The whole work must be studied 

 as a unit, and with strict reference to the 

 thesis on which it is based. Nevertheless, 

 there are many incidental results which 

 possess interest for all readers, such, for 

 instance, as the effect of alcohol upon 

 plants in causing temporary exaltation of 

 response, followed by depression and pro- 

 tracted period of recovery. The style of 

 Datura Alba was used in these experiments. 

 If the alcohol vapor was blown away and 

 fresh air substituted, the tissues slowly re- 

 covered their normal excitability. • But if, 

 instead of alcohol vapor, dilute alcohol so- 

 lution was applied, the depressing effect 

 was immediate and very great. 



There is nothing In the treatise to sug- 

 gest that the work is not the outcome of 

 a physiological laboratory in Europe and 

 from the hands of a physiologist in Ger- 

 many or England. But the author is an East 

 Indian, much of whose experimental work 

 has been carried on under tropical condi- 

 tions. The greater part of his material 

 has been found in India, where, as in all 

 tropical countries, vegetation does not have 

 the long periods of hibernation characteris- 

 tic of the temperate zones. There must 

 have been at his command a wealth of 



