RELATION OF PLANT PROTOPLASM TO ENVIRONMENT. 267 



some malvaceous and particularly some leguminous seeds, remain in a state 

 of "dormant vitality" for a period of 5 to 50 years at least. That they are 

 living and not dead bodies during all of this period, is shown by their being 

 germinable at any time; by their undergoing a slow but gradual loss in germinating 

 capacity; and that a stage is ultimately reached when life-changes can no longer 

 be started; that is, the irritability of the cells in the albumen and in the embryo, 

 which may have persisted for many years, fails longer to express itself. 



Waller (27) in his electrical blaze-response experiments failed to obtain any 

 evidence of life in such dormant seeds, and felt that he was accordingly placed 

 in a dilemma. He in part tried to escape from it by saying that "it is possible 

 or rather, certain — firstly that our means of chemical investigation are not 

 refined enough to reveal to us the smallest and most infinitesimal changes that 

 may be going on in an apparently dry and perfectly dormant seed; and second 

 it is possible that chemical change may be completely and absolutely arrested 

 (e. g., by low temperature) without that arrest being of necessity final and 

 definite." 



Without at present going further into the subject, we would merely state 

 the fact that under definite environmental states some seeds contain cell pro- 

 toplasm — probably mainly in the embryo — that retains its irritable and chemico- 

 physiological capacity for response through a period of at least half a century, 

 though in a so greatly reduced state of activity that galvanometric records seem 

 to be feeble or unobtainable. 



Before leaving this subject, reference may be made to the peculiar results 

 obtained by Romanes (28) with seeds that were exposed in highly exhausted 

 vacuum tubes for 15 months; or for three months, and thereafter transferred to 

 tubes charged at air pressure with gases or vapors of hydrogen, carbon monoxide, 

 carbon disulphide, ether, etc., for an added period of twelve months. His 

 result was ' * that neither a vacuum of i.oo^.ooo of an atmosphere, nor the atmos- 

 phere of any of the gases and vapors named in the above list, exercised much, if 

 any, effect on the germinating power of any of these seeds." Dyer in the article 

 already quoted states on the authority of another without giving any evidence, 

 that "an injurious effect is ultimately produced." But even granting such, to 

 have secured germination is proof that protoplasm may behave with great 

 endurance to environmental agents. 



In view of statements that have usually been current in the past, as to 

 protoplasmic adaptability and resistance, it might scarcely seem likely that the 

 cells of any vegetative part of a flowering plant could endure a temperature 

 higher than 42°-45° C. And while this may be true for each plant in some one 

 or other of its tissues, if we can show that certain living tissues can be exposed 

 to 60°-70° C, and to direct insolation that roughly corresponds in intensity to 

 this temperature record, or again to temperatures as low as - 60° C. for hours of 

 each day, then we have gained a clearer insight into the adaptive capacity of 

 cell protoplasm, seeing that all the cells of any flowering plant are derived from 

 the fertilized egg-cell. 



