No. 3, January, 1922] MORPHOLOGY AND TAXONOMY, FUNGI, ETC. 189 



when the carbohydrate supply is exhausted, a small, non-motile, coccus form appears which 

 is designated as the "non-motile, pre-swarmer stage." In the presence of saccarose, certain 

 other carbohydrates, and phosphates the coccoid form increases in size to double its former 

 diameter, but still remains non-motile. This is the "second pre-swarmer" stage. The 

 "second pre-swarmer" now becomes ellipsoidal and develops high motility. This is the well 

 known "swarmer" of Beijerinck. The organism in the "swarmer" stage now becomes more 

 elongated, assuming a definite rod form and still remaining motile, though less so. The 

 organism remains in this form as long as the medium contains suflBcient available carbohy- 

 drate. When the organism is placed in neutral soil extract or when the available carbohydrate 

 supply becomes exhausted it becomes highly vacuolated and the chromatin divides into a 

 number of bands. These bands finally become rounded off and escape from the rod as the 

 coccoid "pre-swarmers." The addition of calcium or magnesium to the medium or anaerobic 

 conditions induce the "pre-swarmer" stage. The reaction of the soil has an important effect 

 on the organism. The "pre-swarmer" stage is rapidly produced in calcareous soils, while in 

 acid soils the cells become highly vacuolated and ultimately die. Slightly alkaline soils are 

 capable of supporting vigorous growth without altering the form of the cells. High tempera- 

 tures (30-37°C.) either prevent or postpone the breaking up of the rod forms. — V. H. Young. 



1252. DoNK, P. J. A highly resistant thermophilic organism. Jour. Bact. 5: 373-374. 

 1920. — A description is given of a bacterium isolated from canned corn which is very resistant 

 to high temperatures; the author proposes the name Bacillus stearothermophilus. — Chester A. 

 Darling. 



1253. EsTY, J. Russell. The biology of Clostridiimi Welchii. Jour. Bact. S: 375-429. 

 1920. — Over 100 strains of Clostridium Welchii (Bacillus aerogenes capsidatus) were isolated 

 from various sources and subjected to a rather complete series of tests; the study is arranged 

 under the following headings: Isolation, distribution, morphology, spore formation, cultural 

 characters, chemical characters, classification, thermal death point, pathogenicity, immunity, 

 effects of feeding Clostridium Welchii, and conclusions. — Chester A. Darling. 



1254. Hall, Ivan C. Impure and misnamed stock cultures of obligate anaerobes. Proc. 

 Soc. Exp. Biol, and Med. 18: 314-316. 1921. — Sources of contamination of stock cultures are 

 discussed. — M. M. Brooks. 



1255. Hall, Ivan C. The early history of litmus in bacteriology. Science 53: 388-389. 

 1921. — The article deals mainly with the correction of certain errors but contains a list of 

 9 references. — C. J. Lyon. 



1256. Jones, Dan H. Further studies on the growth cycle of Azotobacter. Jour. Bact. 

 5: 325-342. PL I-4. 1920. — A review is given of some previous work done by the author on 

 Azotobacter, followed by a consideration of the work and conclusions of Lohnis and Smith on 

 "Life Cycles of the Bacteria" (Jour. Agric. Res. 6: 675-702. 1916.) The writer concludes 

 from his observations that no endospores are formed in the 4 species which he studied; a sym- 

 plastic stage occurs in which the individual cells are indistinguishable but numerous gonidia- 

 like granules are present, being liberated when the cells disintegrate; these granules are re- 

 productive bodies. The writer does not accept the conclusions of Lohnis and Smith that 

 2 or more cells unite; he interprets these stages as stages in fission. — Chester A. Darling. 



1257. Kendall, A. I., M. Cook, and M. Ryan. Methods of isolation and cidtivation of 

 anaerobic bacteria. Jour. Infect. Diseases 29: 227-234. 1921. — The present information 

 concerning the group of anaerobic bacteria is regarded as untrustworthy because no precau- 

 tions have been taken to obtain the organisms free from aerobic and particularly anaerobic 

 contaminations. The Barber method for the isolation of single cell cultures is modified for 

 the isolation of single spores of anaerobic bacteria. Brain and meat media are used for the 

 cultivation of the organisms; for peptone medium, a modification of the Hall tube is used. — 

 Selman A. Waksman. 



