1909] 



CURRENT LITERATURE 



423 



It is hardly necessary in a botanical publication to comment on a recent note 

 in Science, entitled Mucor cultures. 1 * The author states that "in the study of 

 the Mucoraceae for several years, some interesting facts concerning the develop- 

 ment or rather non-development of zygospores were observed." In a thousand 

 cultures of Rhizopus nigricans, made from material collected by the author or sent 

 him by friends, as well as in five hundred specimens found growing spontaneously 

 in different places, and in about five hundred other unrecorded observations of the 



- 



fungus (a total of two thousand observations), no zygospores were found. Inocu- 

 lations were made on a number of different media, including Hamaker's corn- 

 bread-muffin combination, and the growth of the cultures was tested in closed 

 jars in H, N, and C0 2 . No zygospores were obtained, and the conclusion is 

 reached that "the absence of oxygen is not a necessary condition for the growth 

 of zygospores/' It is a pity that one who has the time to make observations on 

 2000 cultures should not have taken the trouble to read the recent literature on 

 the subject, to learn in what part of a culture zygospores are produced and under 

 what conditions their formation is possible, and so be in a position to make a con- 

 tribution of some value. Additional information in regard to the relative distri- 

 bution in nature of the two sexual strains of this most common of molds might 

 have been the fruit of so extended a series of observations. 



Appended is a list of species, the thallic condition of which has been deter- 

 mined, arranged according to the type of their sexual reproduction. Following 

 each species is given in parentheses the name of the author who has investigated the 

 zygospores and determined the sexual condition of the species in question. 



Homothallic 



1 - Sporodinia grandis (Blakeslee) 



2 - Spinellus fusiger (Blakeslee) 

 3» 4- Mucors I and II (Blakeslee) 

 5- Mortierella polycephala (Dauphin) 



Heterogamic 



&• Dicranophora (Blakeslee) 

 Zygorhynchus Moelleri (Blakeslee) 



Heterothallic 



1. Mucor Mucedo (Blakeslee) 



2. M. hiemalis (Hagem) 



3. M. silvaticus (Hagem) 



4-9. Mucors III-VIII (Blakeslee) is 

 10. Absidia Orchidis (Hagem) 



11. 



Absidia glauca (Hagem) 



12. Absidia caerulea (Blakeslee) 



8 7* n . , v " ' 13. Absidia repens (Blakeslee) 



°- £>gorhynchus heterogamus (Blakes- r> u . ... m rrcT 



LEE) 



9- Abisdia spinosa (Lendxer) 



14. Rhizopus nigricans (Blakeslee) 



15. Phycomyces nitens (Blakeslee) 



16. Circinella umbellata (Blakeslee) 



17. Cunninghamella echinulata (Blakes- 

 lee) 



18. Choanephora cucurbitarum (Blakes- 



lee) 



19. Helicostylum piriforme (Blakeslee) 



20. Syncephalastrum (Blakeslee) 



21. Mucor N, n. gen. (Blakeslee) 

 —A. F. Blakeslee, Storrs, Conn. 



list. 



I4 Sumstixe, David R. Science N. S. 29:267. Feb. 12, 1909. 



15 Perhaps some of Mucors III-VIII are identical with species already in the 



