No. 1, July, 1920] PHYSIOLOGY 231 



produce any result, the initial effect is an incres piration. This may bo followed b 



decrease if the Miicsi hct ir is euflBoientlj toxic. Nbdeci of respiratii ben the 



concentration is too hro to be toxic. Tl oontradid the id< I by 



Verworn and his pupils that anesthetics ac1 bj decreasing i R. C. Ha 



1530. II \ki;i m.ton, (I. T. Respiration and age of plant organ . . of: 

 Contribution a l'etude des variations de la respiration dl ux avec Page. !:■•. Gen I 

 30:214-225. 1918.] Bot. Gas. 67: 177-179. 1919. 



1531. EbrrmANN. Die Keimungsenergie des Klefenia aniens in Theorie und Praxis. 

 [Germination-energy of pine seeds in theory and practice.] Naturw. Zeil I indw. 

 17:53-57. /'/. 1-2. 1919.— See Bot. Absts. 3, Entry 2026. 



ORGANISM AS A WHOLE 



1532. Allen, E. R. Some conditions affecting the growth and activities of Azotobacter 

 chroococcum. Ann. Missouri Bot. Gard. 6 : 1-44. /'/. / ,fi<j. 1-2. 1919. — Allen rep .-ri- 

 mental data which suggest that "some of the markedly beneficial results observed in cultural 

 solutions" by previous workers are related to phosphorus nutrition of the organism and to 

 maintenance of the proper reaction of the medium. Experiments on the removal and n 



rat ion of the solid phase of those culture media u hich produce a precipitate and on the use "f 

 media which form no precipitate, as well as those with agar as a protective colloid, are 

 gestive; but the author feels that they give no final proof of the mechanism of the men 

 in growth of Azotobacter chroococcum. The beneficial effect of the agar might he explained 

 by the presence of certain nutrients in the agar but this seems less plausible than to consider 

 the agar as a protective colloid. One of the many difficulties which stands in the way of 

 proper development of this line of investigation is the interference of colloids. When colloidal 

 hydrated ferric oxide is used in culture media duplicate results do not check and i' !if- 



ficult to duplicate the work of another investigator where colloids are used. The method of 

 measuring growth for a short incubation period proved to be the only reliable method to be 

 used when dealing with Azotobacter, but wholly inadequate to permit a rigid examination of 

 the influence of different conditions. Bonazzi's method of repeatedly renewing the energy sup- 

 ply and measuring the products of growth of nitrite-producing bacteria is far superior hut 

 applicable to Azotobacter cultures. Since the presence of phosphates and the absence of an 

 acid reaction are known requirements of the culture medium they should be studied in d< 

 before further speculative theories are advanced. — S. M. Zeller. 



1533. Baud, Paul. Les nouveaux modes d'emploi des Mucedinees dans les industries 

 agricoles. [New modes of employing molds in the agricultural industries.] Chimie et Indus- 

 trie 1919 7 . 9 p. 1 fig. 1919. 



1534. Brierly, W. B. Some concepts in mycology — an attempt at synthesis. Trans. 

 British Mycol. Soc. 6: 204-235. 1919— See Bot. Absts. 4, Entry 1061. 



1535. Brown, W. H. Vegetation of Philippine mountains. The relation between the en- 

 vironment and physical types at different altitudes. Philippine Bur. Sei. Publ. 13. 4$i p. 

 PI. 1-41, fig- ISO. 1919— See Bot. Absts. 4, Entry ISO. 



1536. Church, A. H. The plankton-phase and plankton-rate. Jour. Bo- Suppl. III. 

 8 p. 1919.— See Bot. Absts. 4, Entry 182. 



1537. Feilitzen, H. vox. Cultural experiments on moor lands. Jour. Ainer. 1' il Soc. 

 12 : 216-217. 1919— See Bot. Absts. 4, Entry 64. 



1538. Henderson, William F. Some experiments conducted with pure cultures of bread 

 yeast. Trans. Amer. Microsc. Soc. 38: 221-227. PI. 23, 24. 1919— See Bot. Absts. 1. Entry 

 1108. 



