No. 2, December, 1921] PHYSIOLOGY 123 



778. Rosa, J. T., Jr. Pentosan content in relation to hardiness of vegetable plants. Proc. 

 Amer. See. Hort. Sci. 17: 207-210. 1920 [1921]. — A close correlation is shown to e.\ist between 

 pentosan content and vegetable plants in various conditions of hardiness. Plants hardened 

 by exposure to low temperature or by withholding moisture showed much higher pentosan 

 content than non-hardened plants. There is a gradual increase in pentosan content accom- 

 panying the hardening process. The following data, expressed in percentages in terms of 

 fresh weight, show how much the pentosan content increases in going from the non-hardened 

 to the hardened state: Cabbage, 0.207 to 0.G04; cauliflower, 0.191 to 0.403; leaf lettuce, 0.106 

 to 0.402; and tomato, 0.091 to 0.362. — Theauthor advances the theory, "thathardened plants 

 contain a greater proportion of 'absorbed' water in colloidal combination with the pentosans 

 of the protoplasm, which is not frozen upon exposure to moderate freezing temperatures. 

 The protoplasm of hardened plants apparentl}' possesses a greater water-holding power than 

 non-hardened plants, which may be accounted for by the fact that hardened plants have been 

 found to contain increased amounts of pentosans roughly proportional to the degree of hardi- 

 ness." — H. A. Jones. 



RADIANT ENERGY RELATIONS 



779. Katser, E. Influence des radiations lumineuses sur I'Azotobacter. [The influence 

 of luminous radiations on Azotobacter.] Compt. Rend. Acad. Sci. Paris 172 : 491-493. 1921. — 

 In 2 previous papers [Compt. Rend. Acad. Sci. 171: 969-971. 1920 and 172: 183-185. 1921]; 

 the author has reported the influence of different generations of the organism upon the capacity 

 of Azotobacter to fix nitrogen, also the influence of different colored lights and of darkness; 

 likewise the relation to carbohydrate consumed. The experiments reported in the present 

 paper constitute a study of nitrogen fixation by Azotobacter of the 12th generation, likewise 

 the effect of changing the color of the radiations. Organisms which had been cultivated to 

 the 12th generation under green rays, were placed in 2 separate glasses containing the nutri- 

 ents; one was exposed to green and the other to yellow rays. This was repeated for the other 

 colors. The 12th generation in all cases fixed less total N than the 6th. In all cases, except 

 the one where blue w^as replaced by yellow, an increase of the total N fixed followed a change 

 of color in the light. Likewise in 4 of the 6 cases, white to blue and green to yellow being the 

 exceptions, change of color in the rays was responsible for the increase in N fixed per gram of 

 carbohydrate decomposed. — L. J. Klotz. 



TOXIC AGENTS 



780. B. [Rev. of: Wintersteix, Hans. Die Narkose in ihrer Bedeutung fiir die allge- 

 meine Physiologie. (The significance of narcosis in general physiology.) S19 p. J. Springer: 

 Berlin. 1919. Unbound, 16 marks; bound, 18 marks.] Zeitschr. Phys. Chem. 96: 377. 1920. 



781. Burgess, Kenneth E. The toxicity towards Staphylococcus of dilute phenol solu- 

 tions containing sodium benzoate. Jour. Phys. Chem. 24: 738-740. 1920. — The author con- 

 cludes that the phenomena observed by Lemon (see Bot. Absts. 10, Entry 786), which were 

 not in accord with Miller's hypothesis (see Bot. Absts. 10. Entry 787) of the alteration of chem- 

 ical potential of phenol solutions by salts, were produced by injury of the Staphjdococcus cells 

 due to low concentration of the medium, thus confirrhing the results of Laird (see Bot. Absts. 

 10, Entry 784).—//. E. Pulling. 



782. Frazer, Chas. G. Methylene blue as indicator in determining the toxicity of phenol 

 and phenol-salt solutions towards yeast. Jour. Phys. Chem. 25: 1-9. 1921. — Solutions con- 

 taining phenol and sodium chloride, of such compositions as to be in equilibrium with the same 

 solution of phenol in toluene or in kerosene, are isotoxic towards yeast if the ability of the cells 

 to stain with methylene blue be adopted as a criterion of death. If inability to form colonies 

 on wort-agar be adopted, the solutions containing salt are more toxic than the phenol solutions 

 of the same chemical potential (see Bot. Absts. 10, Entry 787). It is suggested that cells may 

 lack the power to form colonies and yet not be "dead," since "emaciated" cells are gendlfally 

 believed to lack this power, thus less poisoning would be required to produce this condition 



