204 BOTANICAL GAZETTE |ocTOBER 
contrasts than to attempt to secure more accurate records by 
averaging the grades of a relatively few contrasts which had been 
several times repeated. If any of the cultures had become infected 
or in any other way appeared abnormal, the contrasts of course 
were repeated. In a few cases, especially in the earlier contrasts 
with C. bertholletiae, zygospores were found where, on the basis of a 
strict sexual dimorphism, they would not be expected. A repetition 
of these contrasts under improved technique gave the results incor- 
porated in table VILA, and indicated that their earlier aberrant 
behavior was due to infection with the opposite sexes of the same 
species. All contrasts with species of Cunninghamella have been 
grown in the incubating oven at 24°-27°C 
CUNNINGHAMELLA ELEGANS 
Table IV shows the tests with C. elegans. Twelve races were 
used as testers, and in all 426 contrast combinations were made 
with the total forty-two races. Of these, twenty-five were plus, 
sixteen were minus, and one, on account of its failure to show 
reactions in any of the combinations tested, has provisionally been 
listed as a neutral. 
CUNNINGHAMELLA ECHINULATA 
Table V shows the tests with C. echinulata. All the 153 possible 
contrast combinations were made with the total eighteen races. 
Of these, ten were plus, eight were minus, and none failed to show 
a sexual reaction in at least two contrast combinations. Since no 
reactions occurred when races with like sign were contrasted 
together, only the contrasts between plus and minus races are 
represented in the table. 
CUNNINGHAMELLA A 
Table VI shows the tests with the undetermined species of 
Cunninghamella provisionally termed Cunninghamella A, It is a 
form intermediate in appearance between C. bertholletiae and C. 
echinulata, and was at first confused with them. In tube cultures 
it approaches more nearly the habit and color of C. echinulata. 
From this species, however, it may readily be distinguished micro- 
scopically, especially by the lack of conspicuous echinulations on 
the conidia. The form, however, needs a more careful study than 
