ZOOLOGY — BLAKESLEE. 275 



ZOOLOGY. 



Blakeslee, Alfred F., Botanisches Institut, Halle, Germany. Grant 

 No. 160. Investigation of sexuality in lower fungi. $1,000. 



Abstract of Report. — The grant was made for investigation at 

 German universities, and Dr. Blakeslee reports from Germany that 

 it seems desirable to continue the work on the sexuality of black 

 molds (Mucors). It is found that the two sexes separate in distinct 

 races, and are apparently capable of keeping their sexual character 

 to an indefinite number of generations by non-sexual reproduction. 



The preliminary summary of the previous work has been pub- 

 lished in Science, n. s. , vol. 19, p. 864. The importance of the 

 subject to botanical physiology may be inferred by reference to Pro- 

 fessor Duggar's address before the International Science Congress 

 in St. Louis (see 23d issue of Science, 1905, p. 951). The sexual 

 spores are very capricious and difficult to germinate, requiring, when 

 they germinate at all, a wait of upward of five months after being 

 sown. Only in the case of two species, from a large number 

 attempted, have germinations been obtained. In one of these the 

 non-sexual spores resulting from the germination are male, female, 

 and hermaphroditic. The non-sexual spores from the hermaphro- 

 ditic plants in turn produce male, female, and hermaphroditic spores. 

 The hermaphroditic condition not being transmitted to all the non- 

 sexual offspring, it is necessary to carry on the hermaphroditic 

 plants in a poor condition to make the transfers of the vegetative 

 growth every other day. Many interesting problems with this her- 

 maphroditic race present themselves. The influence of external 

 conditions upon the determination of the sex ought to be tested, 

 since the race is apparently in a labile condition. 



During the present year Dr. Blakeslee has discovered the sexual 

 spores and determined the sexual conditions in the following forms : 

 Circinella, Absidia repens, Absidia sp. (?), Helicostylum % Syncepha- 

 lestrum, Cunning hamclla, and several of the genus Mucor. In these 

 forms, with the possible exception of Circinclla, the sexual spores 

 had never been known. By finding the sexual spores of Cunning - 

 hamella, the position of this species among the Mucors is established, 

 whereas it had formerly been classed as one of the Fungi Imperfecti 

 in the genus Oedoccphalum. Dr. Blakeslee has in process of publica- 

 tion in the Botanical Gazette an article on this species and on a unique 

 new genus which shows relationships with the Mucors. Finally, by 

 germination of the zygospores, he has obtained in one species an 

 hermaphroditic race in addition to the male and female races which 

 are characteristics of the species. 



