Januaet 14, 1910] 



SCIENCE 



61 



would afford some clue to the enzymatic 

 activity of the stimulated fungus as com- 

 pared with the normal growth, and experi- 

 ments seem to show pretty clearly that 

 there is greater proportional en2ymatie 

 activity in the former than in the latter. 

 The same point is even more clearly illus- 

 trated by the various researches on the 

 influence of chemical irritation upon alco- 

 holic fermentation by yeasts. A variety of 

 substances in minimal doses have been 

 found to increase the fermentative activity 

 of these fungi. While in such cases we 

 are, of course, dealing with extracellular 

 enzymes, it is not unreasonable to suppose 

 that by analogy similar excitation follows 

 with the intracellular enzymes. The intra- 

 cellular enzymes are the ones which we may 

 legitimately suppose to be connected more 

 or less directly with the metabolic activity 

 of the living organism. Now if anabolic 

 activity is connected in any way with the 

 reversible action of enzymes — as seems 

 likely — we have here another link in the 

 chain of evidence as to the real nature of 

 chemical stimulation. We may hope in 

 time to reduce it entirely to a question of 

 enzyme formation. In order to do so we 

 must devise more precise means for investi- 

 gating the intracellular enzymes in the 

 plants experimented upon and to determine 

 if there is any quantitative difference as a 

 result of stimi;lation. If it can be proved 

 that this causes a relative increase in syn- 

 thesizing enzymes in the fungus hyphse a 

 long step toward a more complete under- 

 standing of the processes will have been 

 made. It should be acknowledged that at 

 present such considerations are in a meas- 

 ure purely speculative, yet not speculative 

 to the extent of being other than founded 

 on the meager knowledge at hand. There 

 is nothing improbable in such conclusions. 

 The synthetic action of enzymes is a ques- 

 tion which is more and more attracting the 



attention of the investigator, and while the 

 results along these lines are comparatively 

 new and relatively few in number, they are 

 sufficiently conclusive to permit of a broad 

 application of the principle involved. I 

 wiU cite only one instance, and that in rela- 

 tion to an extracellular enzyme, where iso- 

 maltose has been synthesized from glucose 

 by the action of maltase and, further, where 

 the same enzyme was utilized in the sjoi- 

 thesis of the glueoside amygdalin. Grant- 

 ing then that we may have in enzymes 

 active agents in the constructive work of 

 the organism, it is possible to understand 

 how an increase in enzymatic activity could 

 explain many of the phenomena connected 

 with the response to chemical irritation. 



There still remains, of course, the most 

 fundamental question why and in what 

 manner the specific irritants used affect the 

 quantitative and even perhaps the qualita- 

 tive formation of enzymes, and here there 

 is no ready or sufficient answer to give. 

 At first glance it does not appear to be con- 

 nected with their dissociation in weak solu- 

 tions, for non-electrolytes like morphine 

 give a reaction as weU as dissociable salts, 

 although it is to be remarked that the con- 

 centration required with the former is 

 many times greater than with the latter. 

 If, as is believed by some, the poisonous 

 action of salts depends on the degree of 

 their dissociation, it is probably equally 

 true that the stimulative action of minimal 

 doses of these same salts is influenced by 

 this same factor. But this assumption 

 does not dispose of the large class of non- 

 electrolytic poisons (and consequently 

 stimulants), although I venture to suggest 

 that the introduction of such substances 

 into the sphere of protoplasmic activity 

 may result in the formation by the proto- 

 plasm of by-products which are dissociable 

 poisonous substances. Such an explanation 

 would help to account for the large doses 



