Igo BOTANICAL GAZETTE [OCTOBER 
and plus and minus strains of Mucor V and the plus strain of 
C. elegans. The positive and negative results are assembled in a 
table. The sexual condition seemed to BurGER so hopelessly 
confused that he was led to the following conclusions contained 
in his summary: 
1. In Cunninghamella there does not exist sexual dimorphism. 
2. C. echinulata plus and minus, or Mucor V plus and minus as separated 
by BLAKESLEE, are unable to form progametes or gametes when contrasted 
with any one of twenty-six cultures of C. bertholletiae. 
any of these cultures of C. bertholletiae were able to form zygospores 
whines: contrasted with certain other cultures of this same species. 
4. There exists a selective power in some strains to form zygospores with 
certain other strains. This condition of pseudoheterothallism cannot be ex- 
plained at present 
5. There exists a condition in some strains which might be called hermaph- 
roditism 
6. in none of the hermaphroditic strains did branches of the same hyphae 
conjugate. 
7. Zygospores were produced only when two strains were contrasted whose 
gametes were compatible. 
It will be well to examine this summary to see whether the 
rather sweeping conclusions are warranted from BURGER’S own 
data, assuming for the moment that these data are not open to 
criticism. The results of his contrasts are more readily compared 
if his table be rearranged as shown in table I. The six testers of 
C. bertholletiae are placed at the top, together with the plus race of 
C. elegans and of Mucor V, which were also used as testers. On 
the side, grouped according to sex, are placed the twenty-six races 
with which the testers were contrasted; H stands for imperfect 
hybridization, Z for zygospores. If the latter is inclosed in paren- 
thesis, it indicates the occurrence of zygospores in a contrast where 
they would not be expected on the basis of a strict sexual dimor- 
phism. No grades are given in table I, since none are presented 
in the original paper. 
The sexual behavior of the twenty-six races of C. bertholletiae 
shown in the table I is not so badly mixed as even BuRGER himself 
was apparently led to believe from his method of analyzing the 
‘data. He says: “Nos. 1 and 2 have always remained constantly 
