4i 8 



BOTANICAL GAZETTE [may 



Descriptive text of physiological charts (90 pp., including small reproductions of 

 the charts which he published in conjunction with Laurknt) ; Letter prefatory 

 to de Wildeman's Flore des Algues de Belgique; An elementary lesson on Darwin- 

 ism (106 pp.; an admirably clear and brief presentation, which appeared first 

 in 1900 and is now printed as he had revised it for a third edition). This volume 

 closes with three posthumous articles: Plants in contrast with other beings; 

 What there is in a plant; The epopee of a ray of sunlight. 



These volumes, as well as the more strictly scientific ones, will form a worthy 

 memorial of this distinguished savant, whose writing is always luminous and 

 inspiring. His bibliography, though voluminous (287 titles, as we learn from an 

 interesting biography just published*), is remarkable, not alone for its extent, but 

 for its value. To have all his work collected is a real boon- C. R. B. 



NOTES FOR STUDENTS 



Papers on mucors. -Two valuable papers, largely taxonomic m character, 

 have recently appeared on the mucors. In two ways they show an advance over 

 other taxonomic work in this confused group. In the first place the center 10 

 fungus cultures maintained by the Association Internationale des Botamstes 

 been made use of, and the species investigated were compared as far as possi 

 with named cultures from this and from other sources. Provided ™ ntamin !\ 

 of cultures in the source of supply is avoided, this center in Amsterdam alio 



l * . ,-■ iii__^f :«^Dacina value 



determinations 



a. ica,u_y mcuiuu ui ^iit^ivin^, uj-» uv,iwii»«u W vw A\na tO 



to mycologists. In the second place the differentiation of species accora g 



forms 



item in the classification, and in heterothallic species the production of ^P^ 

 when a given strain is grown in contact with the opposite strain of a known p 

 is used to establish its specific identity with the form tested. t dv of soil 



Hagem 10 announces his paper as a preliminary contribution to a s ay ^^ 

 mucors. By exposing Petri-dish cultures to the air and allowing the spo^ ^ ^ 

 fall on them to develop mycelial colonies, he finds with Saito that sp<K ^ 

 mucors, both absolutely and relative to other molds, are unexpec te ^^.^ 

 quent occurrence in the air. Only seven species were thus found. ^^ gown 

 ing the mucor flora of the soil, samples from different kinds of soi s^ ^^ 

 on various nutrient substrata, and the resulting growths isolated in PJ^.^ and 

 Sixteen different species, confined to the genera Mucor, RhlzopUS ' Qt Rictus, 

 Zygorhynchus, were found, of which six are described as new, viz., & ^ ^.^ 

 M. sphaerospoms, M. griseo-cyanus, M. silvaticns, M. norvegicus, a. ^ ^ 

 glauca. Four new forms are added to the list of heterothallic specif fa 



Mucor 



9 Fredericq, Leon, and Massart, Jean, Notice sur Leo ErreR > 



m 



embre de 



V Academic. i2mo. pp. 153. Brussels: Hayez. 1908. yidensk-' 



10 Hagem, Oscar, Untersuchungen uber norwegische Muconneen, 

 Selsk. Skrifter. I. Math.-Nat. Kl. No. 7. pp. 50- 19 08 - 



