Colchicine had little effect on dry might, nitrate, and phosphorus uptake, during a 48-hour period, by 5-day-oId mycelium of Cunninghamella sp. except at 10 p.p.m. concentration of the chemical when the phosphorus content was higher. The drug also induced a higher percentage incorporation of hosphorus into organic compounds, while protein building was Lowered particnerly in the presence of 20 p.p.m, of colchicine. The latter phenomenon was accompanied by excessive accumulation of peptide nitrogen mostly in the external medium.Further, high concentrations of colchicine seemed to inhibit the rate of nitrate assimilation.