No. 3, January, 1922] PHYSIOLOGY 203 



that betain is not toxic to Phaseolus may indicate that this compound is normally present in 

 this plant, but tests made on large quantities of extracts of plants at the time of inception of 

 flowering failed to demonstrate this substance. It was also shown that the tartaric acid ex- 

 tract of these plants did not contain the pyrrolic bases of Pictet. Esterin, which is normally 

 present in Phytosligma, is extremely toxic to Phaseolus and Lycopersicum. (7) The capacity 

 for oxidation of some compounds was studied by incubating them with the pulp of Spinacia in 

 an atmosphere of oxygen. The following are the results: Pyrocatechin, morphine, theobro- 

 mine, cocaine, atropine, butyric and isobutyric acids are oxidized, while guaiacol, codeine, 

 caffeine, methyl-,ethyl-, and propylamines are not oxidized. When injected into growing Zea 

 plants morphine, caffeine, theobi'omine, butyric and isobutyric acids are oxidized, whereas 

 codeine is not. (9) Tannin is only slightly if at all absorbed by growing Phaseolus, Solanum, 

 Zea, and Nicotiana but it appears to induce a general dwarfing, that is the production of a 

 normal dwarf plant. Inoculations led to the same results. As a summary of the conclusions 

 the following may be stated : The amines studied are distinctly toxic while the amino acids are 

 not. Toxicity increases with the degree of hydrogenation. Compounds with condensed 

 benzene nuclei are more toxic than those with single benzene rings. Toxicity is not connected 

 with the length of the carbon chain in the acids. Organic bases are distinctly toxic. The 

 methyl radicle in the compounds studied is not toxic. Plants appear to require the stimula- 

 tion of alkaloids and so utilize the compounds of decomposition, such as xanthine, through the 

 introduction into such molecules of alcohol or acid radicles. Only such plants as normally 

 contain a given poison are immune to its effects. — A. Bonazzi. 



1343. DuGGAR, B. M. The nutritive value of the food reserve in cotyledons. Ann. 

 Missouri Bot. Gard. 7: 291-298. 1920. — Ex-periments with Canada field peas show "that for a 

 growth interval of 24 days the removal of the cotyledons after the second day induces a marked 

 depression in the growth rate and this depression is increasingly less, until, when the removal 

 of the cotyledons occurs after 7 days, the amount of growth is very nearly the same as in the 

 control, with cotyledons intact." The cotyledons are practically exhausted in somewhat 

 less than 10 days. In the case of corn effects are neither so striking nor permanent as in peas. 

 The substitution for cotyledons of peas of such organic nitrogenous nutrients as glycocoll, 

 alanin, sodium asparaginate, and sodium nucleinate yielded no proper compensation for the 

 loss of cotyledons, but it is hoped that further experiments along this line where plants are 

 grown under sterile conditions may reveal the nature of the special growth-inducing agent 

 furnished by cotyledons. — S. M. Zeller. 



1344. Gerretsen, F. C. Uber die Ursache des Leuchtens der Leuchtbakterien. [The 

 causes of the light in the luminous bacteria.] Centralbl. Bakt. II Abt. 52: 353-373. PL 2. 

 1920. — This investigation was undertaken from the point of view that production of light in 

 luminescent bacteria is due to an enzyme. The relation of the constituents of the culture 

 media to the production of light was carefully studied. In view of the occurrence of so many 

 luminescent organisms in the sea, the role of sodium chloride was carefully investigated. It 

 was found that CI could be replaced by other anions without materially influencing the light 

 production. The cation, however, could be replaced only by Mg without greatly inhibiting 

 light production. When both anion and cation are replaced the production of light is 

 considerably less than it is in solutions containing sodium salts, or magnesium chloride. 

 The peptones may serve both the nitrogen and carbon requirements of the bacteria, and for 

 the production of light cannot be replaced by any other source of nitrogen. Sterile fish bouillon 

 treated with warm lye and subsequently oxidized with bromine water produced a greenish 

 light similar to that emitted by bacteria. The hexoses have a favorable influence on light 

 production. This may be partly due to the formation of acids which neutralize the toxic alka- 

 line cleavage products of the peptones. Ultraviolet light was found to be an excellent means 

 for killing the organisms without destroying the light function. A light-producing substance, 

 photogen, is produced intraccUularly by the enzyme photogenase. The production of light 

 is purely a chemical process and is brought about by the oxidation of the photogen by the oxi- 

 dase luciferase. — Anthony Berg. 



