GROWTH AND DEVELOPMENT OF BACTERIA. 35 



C. ; though species exist that will multiply at as high a 

 temperature as 70 C. and others as low as C. The 

 studies of Globig 1 , Miquel 2 , and Macfadyen and Bloxall 3 

 have demonstrated that there exist in the soil, in water, 

 in faBces, in sewage, in dust, and, in fact, practically 

 everywhere, bacteria that under artificial cultivation show 

 no evidence of life at a temperature lower than 60 to 

 65 C., and would even grow at as high a temperature 

 as 70 to 75 C., degrees of heat sufficient for the coag- 

 ulation of albumin. Rabinowitsch 4 has likewise de- 

 scribed a number of species of these " thermophilic " 

 bacteria, as they are called, but states that it was possible 

 in her experiments to obtain evidence of their growth at 

 a lower temperature (34 C. to 44 C.) as well as at the 

 higher temperature mentioned by preceding investiga- 

 tors. The most favorable temperature for the develop- 

 ment of pathogenic bacteria is that of the human body, 

 viz., 37.5 C. There are a number of bacteria com- 

 monly present in water, the so-called normal water bac- 

 teria, that grow best at about 20 C. 



In general then, from what has been learned, it may 

 be said that for the growth and development of bacteria 

 organic matter of a neutral or slightly alkaline reac- 

 tion, in the presence of moisture and at a suitable tem- 

 perature, is necessary. From this can be formed some 

 idea of the omnipresence in nature of these minute 

 vegetable forms. Everywhere that these conditions 

 obtain bacteria can be found. 



1 Globig : Zeitschrift fur Hygiene, Bd. iii. S. 294. 



2 Miquel : Annales de Micrograph^, 1888, pp. 4 to 10. 



3 Macfadyen and Bloxall : Journal of Path, and Bact., vol. iii. Part I. 



4 Rabinowitsch : Zeitschrift fur Hygiene u. Infectionskrankheiten, Bd. xx. 

 Heft 1, S. 154 to 164. 



Of THE 



UNIVERSITY 



Of 



