SMITH— MECHANISM OF OVERGROWTH IN PLANTS. 439 



II. Chemical Findings. 



Slide No. i (Table I.) shows the chemical findings. On this 

 slide I have starred the substances with which I have now pro- 

 duced overgrowths in plants and have italicized those which Dr. 

 Jacques had previously found in his experiments on animal eggs to 

 be most effective in causing unfertilized eggs to begin to grow.^ 

 That there should be so many of these egg-starting substances ex- 

 creted by a tumor-producing parasite is not only astonishing but 

 extremely suggestive. z\ll of them are substances which pass read- 

 ily through protoplasmic membranes. 



TABLE L 

 Showing Products of Bacterium tiimcfacicns. 



* Am»io)iia Acetone 



* Amines • * Acetic Acid 



* Aldehyd * Formic Acid 

 Alcohol Carbonic Acid (?) 



I have added carbonic acid of my own accord, since I did not 

 ask the chemists to search for it: (i) because the crown-gal! 

 schizomycete must be very unlike other organisms if it does not 

 produce some carbonic acid as the result of its growth, although 

 certainly not enough is developed to appear in fermentation tubes 

 as the gas COo ; (2) because the excess of leaf -green (chlorophyll 

 bodies, which assimilate COo) in the deeper tissue of galls on Paris 

 daisy suggests presence of carbonic acid in excess of these tissues ; 

 and (3) because carbonic acid also is one of those substances found 

 by Loeb to stimulate the development of unfertilized eggs. My 

 experiments are still under way, none of them are really completed, 

 and today I will only call your attention to a few of my results, some 

 of which have already been published,- while others are here men- 

 tioned for the first time. I would call attention especially to the 

 substances the names of which I have starred as compounds with 

 which to experiment singly and combined, and in a great variety 

 of dilutions. With each one of these substances, in the absence of 

 bacteria, I have obtained on suitable plants decided overgrowths, 



^ Loeb, " Artificial Parthenogenesis and Fertilization," 1913. 

 -Jour. Agric. Research, January 29, 1917. 



