Apkil 7, 1911] 



SCIENCE 



545 



minutes were not sterile. Ttie effect of this treat- 

 ment on germination was not tested. 



Immersion in HgCL 1-1,000, for 2 minutes and 

 washing eleven times in sterile water did not result 

 in sterility. This treatment did not reduce the 

 percentage of germination of the seeds. 



Seeds immersed in 10 per cent, formaldehyde 

 for 80 minutes were sterilized only in a few in- 

 stances. The germination was reduced 3 per cent. 



Seeds were first put into 95 per cent., alcohol 

 for 10 minutes and then into 10 per cent, formal- 

 dehyde for periods ranging from 15 minutes to 6 

 hours. Only those treated 6 hours in formalde- 

 hyde were sterile. The germination of the seeds 

 treated 6 hours was reduced 65 per cent. Ten 

 minutes lq alcohol did not reduce the percentage 

 of germination. 



Seeds were first put into water in a vacuum 

 chamber and the pressure reduced to 3 mm. for 

 210 minutes. A portion of these seeds, after being 

 placed for 30 minutes in 10 per cent, formalde- 

 hyde, was sterile, but the seeds did not germinate. 

 The vacuum treatment alone did not reduce the 

 percentage of germination. 



Apparently the air in seeds prevents the en- 

 trance of disinfecting solutions and protects the 

 bacteria. 



Method of Keeping Bacteria from Growing 



Plants: J. K. Wilson and H. A. Hasdino. 



The main avenue of infection for experimental 

 plants is through the air. 



Of the many ways which have been suggested 

 for preventing this infection none of them are 

 simple and effective. 



Harrison and Barlow have published on a 

 method for growing legumes on agar in Erlen- 

 meyer flasks. This method can be improved by 

 growing plants in sterile Mason jars, using sterile 

 seeds and earth. Exchange of gases is provided 

 for by soldering a i-inch tube into the metal jar 

 top, plugging the tube with cotton and covering it 

 with an inverted test tube to reduce the chances 

 of contamination and to check evaporation. 



Alfalfa planted in such jars, in sterile sandy 

 soil to which 10 per cent, of water has been added, 

 grew thriftily during four months without being 

 watered or the jars being opened. 



(The jars exhibited contain alfalfa planted 

 August 13, 1910, and the jars have not been 

 opened since that date.) 



Bactericidal Properties and Variations in the 

 Agglutinin Content of Antimeningococcic Sera: 

 Lawkence T. Clark. 



Serum obtained from the horse which has re- 

 ceived subcutaneous injections of first modified 

 and later unmodified polyvalent suspensions of the 

 meningococcus, acquires measurable quantities of 

 agglutinin. Intraperitoneal injections of similar 

 suspensions, either mono- or poly-valent, produce 

 in the ram a serum of markedly greater agglu- 

 tinating power. 



Homologous sera produced from sis cultures 

 respectively, by intraperitoneal injections in the 

 ram, gave distinctly specific agglutinative reac- 

 tions with but one exception — sera 4 and 6 and 

 cultures IV. and VI. being interchangeable with 

 similar results. 



Polyvalent antimeningococcic ram serum pos- 

 sesses decided bactericidal activity, as demon- 

 strated by its effect in combination with comple- 

 ment on fresh living suspensions of the meningo- 

 coccus. 



Studies on Immunity in White Sats and Mice 

 against Spirochwta duttonii: D. H. Bekgey. 

 White rats and mice that have recovered from a 

 weU-marked infection with Spirochceta duttonii 

 have a high degree of acquired immunity against 

 the organism. The serum of such immune rats 

 and mice serves to protect normal animals against 

 the infection. 



The degree of immunity developed is not always 

 absolute, though it is always suiEcient to induce a 

 pronounced alteration in the severity and course 

 of the infection. If infection occurs, the onset is 

 delayed, the number of organisms in the blood is 

 relatively small, relapses are infrequent, and a 

 fatal termination of the disease is prevented. 



The protective substances in the blood of the 

 immune animals consist of at least three types of 

 antibody. Agglutinins are present early in the 

 disease. Bacteriolytic substances are developed as 

 shown by the degenerative changes in the organ- 

 isms toward the close of the disease. Besides these 

 tropic substances are undoubtedly of far greater 

 importance in bringing about the very rapid di- 

 minution in the number of organisms in the blood. 

 The final elimination of the organisms from the 

 blood of the infected animals rests upon their 

 englobement by the free and fixed cells of the 

 body through the influence of the tropic sub- 

 stances. 



Agglutination of B. choleroe suis during the Pro- 

 duction of the Dorset-Niles Serum: Ward Gilt- 

 neb. 



