218 BOTANICAL GAZETTE [OCTOBER 
3. BURGER’s paper on Cunninghamella, in which he concludes 
that sexual dimorphism does not exist in this genus, is discussed 
(1) from the standpoint of his own data, (2) from the standpoint 
of our experience, and the decision is reached that his conclusion 
is not warranted. 
4. Data on Cunninghamella elegans, Cunninghamella A (an un- 
determined species), C. echinulata, and C. bertholletiae give a total 
of 2250 contrasts between a total of 202 races. 
5. In C. bertholletiae certain contrast combinations lead to 
imperfect sexual reactions when zygospores might be expected. 
6. In none of the species were races found which reacted as 
sex intergrades. 
7. It is concluded that so far as the material investigated is 
concerned Cunninghamella is sexually dimorphic. 
STATION FOR EXPERIMENTAL EVOLUTION 
3 PRING Harpor, N.Y. 
LITERATURE CITED 
1. BLAKESLEE, A. F. Sexual reproduction in the Mucorineae. Proc. Amer. 
Acad. 40:205-319. 1904. 
2. ———, Two conidia-bearing fungi, Cunninghamella and Thamnocephalis. 
Bor. Gaz. 40:16I-I70. 1905. 
, Zygospore germinations in the Mucorineae. Annales Mycol. 
4:1-28. 1906 
4. , Zygospores and sexual strains in the common bread mold, Rhizopus 
nigricans. Science N. S. 24:118-122. 190 
, Differentiation of sex in thallus, piccionhyie, and sporophyte. 
Bor. Ga 42:161-178. 1906. 
6. ———, Nature and significance of sexual differentiation in plants. 
Science N. S. 25:366-372. 1 
, Heterothallism in bread mold, Rhizopus nigricans. Bot. Gaz. 
43: 415-418. 1907. 
, Papers on mucors. Bor. GAz. 47:418-423. 1909. 
, Sexual reactions between hermaphroditic and dioecious mucors. 
" Biol. Bull. 29 :87-103. I9IS5. 
10. , Sexuality in mucors. Science N. S. 51:375-382, 403-409. 1920. 
II. , Mutations in mucors. Jour. Heredity 11:278-284. 1920. 
12. BLAKESLEE, A. F., Wricu, D. S., and CartLepcE, J. L., Technique in 
contrasting mucors. Bot. GAz. 72:162-172. 1921. 
3. 
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