of the media commonly employed "by my~*bo"'^b3uist may contain 

 (perhaps a still more difficult undertak:' rp) • In order to 

 "be able to proceed immediately to the prohlem ol temperature 

 Influence this whole matter of nutritional conditions was ig- 

 nored. An that was done in this connection was to he sure 

 that the medium employed would support what appealed to he 

 excellent growth of all four fungi, and to take precautions 

 so that practically the same medium might always he used 

 throughout the entire study. Since corn-meal agar is an 



infusion of corn-meal and agar-agar shreds, both of them ex- 

 ceedingly complicated, unknown and variahle materials, it vas 

 feared that different batches of this mediui - Lght v "3 very 

 different (especially since corn-meal is known to alter marked- 

 ly with time), and an attempt was made to avoid this danger 

 "by preparing enough medium at the beginning for the entire 



investigation, mixing it thoroughly in a single container ana 

 then preserving it in bottles for future use. That the in- 

 fusion itself might alter with time ,vas of course possible, 

 but various repetitions of the experiments indicated clsa - 

 ly that such alteration (if it occurred) was not of such na- 

 ture and magnitude as to alter the growth of the fungi when 

 ether conditions were the same. I" is assumed, therefore, 

 that the medium was alike for all cultures. Indeed, the 

 only way by which it might be determined whether two lots of 

 media are physiologically alike is to subject them to the 

 physiological test of cultures with all other conditions 

 alike. 



24 



