222 GENERAL MICROBIOLOGY 



Are any of the types isolated related to pathogenic forms? 

 May pathogenic bacteria be isolated from air? If so, 

 under what circumstances? 



How do microorganisms enter the air? What types of 

 microorganisms are most apt to be present in air? What 

 is the explanation for this? 



What other methods may be employed for obtaining 

 quantitatively the bacteria in the air? 



Of what importance is the quantitative or qualitative 

 determination of microorganisms in air? 



17. Give data and results in full and draw any conclu- 

 sions permitted. Point out any practical applications of the 

 above. 



REFERENCES 



RUEHLE, G. L. A. and KULP, W. L.: Germ content of stable air and 



its effect upon the germ content of milk, Bui. 409, N. Y. Expt. 



Sta., 1915. 



MARSHALL: Microbiology (1911), pp. 185-191. 

 EYRE: Bacteriological Technic: 2d Ed. (1913), pp. 468-470. 

 BESSON: Practical Bacteriplogy, Microbiology and Serum Therapy, 



transl. by Hutchens (1913), pp. 862-867. 

 CHAPIN, C. V.: The air as a vehicle of infection. Jour. Amer. Med. 



Ass'n., Vol. LXII, pp. 423-430 (1914). 

 WINSLOW,- C. E. A.: Bacteriology of air and its sanitary significance. 



Cent. f. Bakt. Abt. II. Bd., 42, p. 71 (1914). 

 WINSLOW, C. E. A. and BROWN, W. W.: The microbic content of 



indoor and outdoor air. Mo. Weather Rev., Vol. XLII (1914), 



pp. 452-453. Abst. in Exp't. Sta. Record, Vol. XXXII, No. 3 



(1915), p. 211. 



