Septembeb 11, 1914] 



SCIENCE 



379 



sity to accept the corresponding position in 

 Vassar College. 



Dh. Lawrence E. Griffin has been ap- 

 pointed professor of zoology in the University 

 of Pittsburgh. 



Dr. Egbert M. Ogden, of the University of 

 Tennessee, secretary of the American Psycho- 

 logical Association, has accepted the chair of 

 psychology at the University of Kansas. 



Dr. Friend E. Clark has resigned his posi- 

 tion as professor of chemistry in Center Col- 

 lie, Danville, Ky., to become professor of 

 chemistry in West Virginia University. 



Samuel "W. Geiser, B.S. (Upper Iowa, '12), 

 has been appointed professor of biology at 

 Guilford College, North Carolina. 



Dean A. Worcester, B.A. (Colorado, '11), 

 has been appointed associate professor of 

 psychology in the University of New Mexico. 



Dr. Harold Chapman Brown, of Columbia 

 University, has been appointed assistant pro- 

 fessor of philosophy in Stanford University. 



Irene Hunt Davis, instructor in chemistry 

 at the University of Washington, has been 

 promoted to be assistant professor of chemis- 

 try. 



The following have been recently appointed 

 to positions in George Peabody College for 

 Teachers: Mr. Charles C. Colby, from the 

 Minnesota State Normal School, as associate 

 professor of geography; Miss Ada M. Field 

 from Teachers College; Miss Blanche Evelyn 

 Hyde from Newton, Mass., as assistant pro- 

 fessors of home economics; Dr. William F. 

 Russell, honorary fellow in Teachers College, 

 as associate professor of secondary education. 

 Dr. Leonidas 0. Glenn, professor of geology, 

 and Dr. John J. Luck, assistant professor of 

 mathematics, of Vanderbilt University, have 

 been secured to give special courses at the 

 college. 



Dr. Theodore Shennan, at present pathol- 

 ogist to the Royal Infirmary of Edinburgh, has 

 been appointed regius professor of pathology 

 (Sir Erasmus Wilson Chair) in the Univer- 

 sity of Aberdeen, in the place of the late 

 Professor George Dean. 



DISCUSSION AND COSBESPONDENCE 

 DO azotobacter nitrify? 



Under the caption of " Fixation of Atmos- 

 pheric Nitrogen " Mr. Dan. H. Jones, in the 

 Transactions of the Royal Society of Canada, 

 Third Series, 1913, Vol. III., Sect. IV.,i gives 

 the results of certain experiments tending to 

 show that the azotobacter form nitrates in 

 their body tissues. He states : 



Cultures of each variety in Ashby's solution 

 when one mouth old gave the nitrate reaction with 

 phenolsulphonic acid oolorimetrie test. As the 

 cultures get older, up to several months, the reac- 

 tion to the test gets slightly stronger. This nitrate 

 is retained almost altogether in the bodies of the 

 organisms. Cultures filtered through Berkefeld 

 filter gave only a trace of nitrate in the filtrate 

 and a strong reaction in the mass of organisms 

 which did not pass through the filter. The filtrate 

 plated out showed that some of the organisms had 

 passed through the filter. But as it took about 

 ten days to filter enough for a test it is possible 

 that the organisms had grown through the filter 

 in that time. Probably the presence of a small 

 number of organisms in the filtrate was respon- 

 sible for the trace of nitrate in the tests. Mass 

 growths on Ashby's agar, when mature, gave a 

 strong nitrate reaction. 



The author does not state to what extent 

 pigmentation had taken place, but as the ma- 

 terial experimented with represented old cul- 

 tures it is probable that a considerable degree 

 of pigmentation was present. He says : 



As the cultures get older, up to several months, 

 the reaction to the test gets slightly stronger. 



The present vrriter was deeply interested in 

 this subject in connection with work which he 

 was doing in 1910 and 1911 and stated in de- 

 scribing some samples of soil used in studying 

 the subject of fixation,^ that 

 a certain sample gave, at the beginning of the ex- 

 periment, aja unsatisfactory growth of azotobacter 

 but thirteen days later another culture made from 

 the same sample gave a heavy membrane in four 

 days on which brown points developed on the 

 eighth or ninth day. 



Again on page 93 of the same bulletin it is 

 stated : 



1 The title of the article is " A Morphological 

 and Cultural Study of Some Ozotobacter. " 



2 Bull. 178, p. 87, Colo. Expt. Sta., 1911. 



