192 BOTANICAL GAZETTE [ocroBER 
those reacting with both plus and minus strains. Referring to 
table I, it will be seen that in only eight contrasts are zygospores 
found where under a strict sexual dimorphism they would not be 
expected. Two of the eight are duplicates, leaving only six dif- 
ferent contrasts showing aberrant reactions. It is not necessary, 
however, to consider more than three races hermaphroditic to 
account for the aberrant results. These three hermaphrodites may 
be variously chosen. Race no. 21 has three aberrant reactions, 
which is the largest number shown by any race. Both races nos. 
14 and 20 show two aberrant reactions each, and may be chosen 
with no. 21 to make up the three hermaphrodites. Since nos. 14 
and 20 are both assumed to be hermaphrodites, the reaction between 
them ought not perhaps to be credited to both of these races. How- 
ever the credit of aberrancy is adjusted between nos. 14 and 20, 
race no. 21 remains the one which gives the largest number of 
aberrant reactions, and therefore of all the twenty-six races it is 
the one most surely shown by BurGER’s data to be a hermaphro- 
dite. This no. 21 is the same as our no. 213, and is the only one 
of the twenty-six races which it has been possible to reinvestigate. 
Its sexual behavior will be discussed more fully later. 
Conclusion no. 1 of BURGER’s summary that in Cunninghamella 
there does not exist sexual dimorphism would seem too sweeping 
a statement in view of the fact that in Mucor and Absidia, which 
are predominantly heterothallic, forms are known, such as Mucor 
heterogamus (which with other similar species has been placed by 
some workers in the genus Zygorhynchus), and Absidia spinosa, 
which are homothallic. Races of two other species of Cunning- 
hamella reported upon in the paper under discussion gave no 
evidence of hermaphroditism, and in consequence the data pre- 
sented warrant the conclusion at most in reference to a single 
species. That in this single species three out of twenty-six races 
showed, in 135 out of a possible 325 contrasts, six reactions which 
were interpreted as indicating hermaphroditism, would render the 
species in the same class with the willows and others of the flowering 
plants called dioecious. That sexual dimorphism, strictly speaking, 
does not exist in higher plants is strongly suggested by past obser- 
vations and experimentation, but the term sexual dimorphism is 
