286 



SCIENCE 



[N. S Vol. XLII. No. 1078 



protozoa. And as a result of this separation, 

 it is possible to eliminate fungi from experi- 

 ments involving the effect of protozoa upon 

 bacterial activity, by making a subculture 

 from the fungi-free solution of bacteria and 

 protozoa (in the cavity of the agar plate). 



Some studies on the comparative value of 

 different media for the development of soil 

 protozoa, somewhat after the manner of Cun- 

 ningham and Lohnis' and others, veere carried 

 out with hay infusion, with and without the 

 addition of .5 per cent, egg albumen (Goodey), 

 peptone, dried blood, soil extract (Lohnis), 

 horse, cow and chicken manures (Martin) and 

 egg albumen. The above media were em- 

 ployed in dilutions of .5 per cent., 1 per cent., 

 3 per cent., 5 per cent, and 10 per cent. 



A condensed table^" of maximum numbers 

 (counts made on five succeeding days by 

 means of the Blutkorperzalilapparat previously 

 described) is given below: 



Summary 

 1. Ten per cent, hay infusion proved to be 

 the most favorable medium for the develop- 

 mient of large numbers of small flagellates, as 

 well as small and large ciliates. Hay infusion 

 in various concentrations, with and without 

 the addition of egg albumen, proved to be well 

 adapted to the development of the organisms. 

 Hay infusion plus .5 per cent, egg albumen 



8 Ounningham and Lohnis, Centr. f. BaJct., II., 

 39 (1914), 596. 



10 Kopeloff, Lint and Coleman, Am. Mic. Soc, 

 34, No. 2 (1915), 149, Jour. Agr. Res., 4, No. 6 

 (1915). 



proved superior to all other media for the de- 

 velopment of ciliates. 



2. Soil extract is an excellent medium, 

 though somewhat inferior to hay infusion plus 

 .5 per cent, egg albumen and with the soil 

 used in this experiment lower concentrations 

 than those recommended by Lohnis, developed 

 protozoa in a shorter period of time. 



3. Three per cent, chicken manure is an 

 excellent medium for the development of small 

 ciliates. 



4. The numbers and species of protozoa 

 which can be obtained from a given soil are 

 largely dependent upon the media employed, 

 time of incubation, as well as the kind of soil 

 used. 



5. In general the order of appearance of 

 protozoa was as follows : small flagellates, 

 small ciliates, large flagellates (if appearing 

 at all) and finally large ciliates. This con- 

 firms Cunningham and Lohnis's observations. 



Nicholas Kopeloff, 

 H. Clay Lint, 

 David A. Coleman 

 New Bkunswick, N. J., 

 February 25, 1915 



SOCIETIES AND ACADEMIES 



THE BOTANICAL SOCLETY OP WASHINGTON 



The Botanical Society of Washington enter- 

 tained at an informal dinner at the Cosmos Club, 

 on Thursday evening, July 22, 1915, Dr. F. K^lpin 

 Eavn, of Denmark, Dr. Otto Appel, of Germany, 

 and Dr. Gentaro Tamada, of Japan. Mr. M. A. 

 Carleton welcomed the guests, each of whom re- 

 sponded. 



Dr. H. B. Humphrey commented on the services 

 rendered to cereal pathology by Dr. Ravn's travel 

 and studies in the United States this season. 



Dr. W. A. Orton gave a full account of the 

 travel of Dr. Appel and his investigations of the 

 potato diseases in this country during the past 

 year. 



Dr. E. F. Smith emphasized the importance of 

 wide travel and experience to botanical investi- 

 gators. 



Dr. C. L. Shear spoke on international phyto- 

 pathology, and expressed a hope that within a 

 short time there may be organized an international 

 society of plant pathologists. 



Perley Spaulding, 

 Corresponding Secretary 



