Zinc and Growth of Aspergillus niger

One may doubt, however, whether the cuts protraying the features of Prince, Rogers, and Munson flatter these leaders.As a whole, the book seems to do well what it is intended to do.-RODNEY H. TRUE. NOTES FOR STUDENTSCactaceae.-It is probable that no monograph of a family is based upon more complete study than the monograph of Cactaceae by BRITTON and RoSE,2 the first volume of which has just appeared.The illustrations are very numerous and admirable, and the colored plates are especially noteworthy.The authors began the study in I904, and since that time the field work extended beyond North America, which was the original limit, so as to include the arid regions of South America as well.Those who are acquainted with the Cactaceae realize that not only are herbarium and field studies necessary, but also greenhouse studies, to discover the different phases that may appear during development.The present volume includes the tribe Pereskieae, with its single genus Pereskia, represented by i9 species, 4 of which are new, and also the tribe Opuntieae, in which 7 genera are recognized, one of which is new (Tacinga).The large genus is Opuntia, with 264 species, grouped into 3 subgenera and 46 series, 32 of the species being new.New species are also described in Pterocactus (3) and Nopalea (2).All of the genera ara illustrated, and of the 312