56 



UNIVERSITY OF WISCONSIN STUDIES 



For the work with molds an agar containing the nutrient salts, 

 potato broth, and cane sugar gives excellent growths, although 

 ordinary nutrient agar serves nearly as well. 



For obtaining the spores it is well to nse a culture a month 

 or two old. Controls were always employed to determine 

 whether the inoculations were successful. Two controls, one 

 made at the beginning and the other one at the end of the ex- 

 periment, were sometimes made but this is scarcely necessary 

 for mold spores possess a remarkable resistance against desicca- 

 tion. 



CULTURES USED 



Representatives of the more common molds were employed 

 in the trials. A black mold of as yet undetermined species 

 represented the Mucoraceae: Aspergillus niyer, Aspcryil- 

 lus fumiyatus, Asperyillus nidulans, Oidiuni lactis and 

 Penicillin in ylancnni were the other forms used. All the 

 forms are exceedingly common and were obtained from the 

 air or from decayed fruits, excepting the Oidiuni which was 

 isolated from milk. Aspergillus funrigatus was included be- 

 cause of its pathogenic powers for animals. 



The following tables pres?nt the results when the spores 

 of these molds were exposed to direct sunlight. 



TABLE I.-MUCOR SP. 



