RHIZOPUS EOT OF STRAWBERRIES IN TRANSIT. 5 



the morphological characters are concerned the fungus under consid- 

 eration when grown under certain conditions agrees very well with 

 his description of Rhizopus nigricans Ehrb. It is evident from his 

 description that Hanzawa studied the fungus under rather uniform 

 conditions, as the measurements given by no means include its limits 

 of variability. 



Fig. 1. — Effect of Rhizopus nigricans on strawberries of the Missionary variety which 

 had stood for two days at room temperature. Each berry in the flask at the right 

 had been inoculated with Rhizopus nigricans. 



In connection with studies on the humidity relations of this fungus 

 (p. 7), the writers found that at a temperature of 20° C. the length 

 of the sporangiophore and the size of the columella vary greatly in 

 air of different humidities. For example, in air with a saturation 

 deficit of 17 mm. of mercury, 2.3 per cent relative humidity, spo- 

 rangiophores are mostly 1 mm. in length, while in saturated air they 

 are from 3 to 4 cm. long. In air with a saturation deficit of 17 mm. 

 of mercury the columellse are mostly 95 to 100 ^ in width ; in saturated 

 air they are mostly from 150 to ISO [j. wide. The size of spores and 



