PLATE II 



Tubers inoculated with Fusarium oxysporum and kept for five weeks at the fol- 

 lowing temperatures and humidities : 

 A. — 25° C, 30 per cent relative humidity. 

 B. — -25° C, 70 per cent relative humidity. 

 C. — 25° C, 100 per cent relative humidity. 



