ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 167 



and their local floras are first described in detail ; and then a systematic 

 account of the species follows, comprising 59 hepatics, 12 sphagna, 173 

 mosses. There are five new species of Bryum, and five new varieties, 

 and much critical work, especially on the Harpidiaceous species of 

 Amhlystegium. A. G. 



Uganda Mosses. — H. N. Dixon {Smithsonian Miscellaneous Collec- 

 tions, 1918, 69, No. 8, 10 pp., 1 pi.). An account of the mosses in 

 Uganda by R. Diimmer and others, twenty-seven species in all, including 

 eight which are new to science. The most interesting of these is 

 Cyathophorum africanuni, an eastern genus hitherto unknown to Africa. 

 'All the novelties are figured. A. G. 



Mosses and Ferns from the Pacific. — K. Rechinger (Denkschr. 

 Alcad. Wiss. Wien, 1914, 89, 441-50 ; see also Bot. Centralbl, 1915, 

 128, 536). An account of the mosses gathered in Hawaii and Solomon 

 Islands determined by V. F. Brotherus ; and of the ferns from the New 

 Guinea Archipelago. Several new species are described. A. G. 



Contributions to the Moss-flora of the Argentine. — V. F. 

 Brotherus {Arlciv for Botanik, 1917, 15, No. 6, 15 pp.). An account 

 of the mosses collected by R. E. Fries in the province of Jujuy, 

 Argentine, and in Gran Chaco, Bolivia, during the Swedish Expedition of 

 1901-2. The climate was dry, and the total number of species collected 

 was forty-six, among them being twelve new species, one of which, a 

 Desmatodon, is of special interest, since no species of that genus had 

 ever been found south of the equator. A. G. 



Thallophyta. 



Algae. 



Axial Rotation of Aquatic Micro-organisms and its Significance. 

 — L. B. Walton (Ohio Journ. of Science, 1917, 18, 6-7). A short note 

 on the result of studies during two years on this subject. In general, 

 the conclusion of the author is that the positively phototactic free swim- 

 ming forms of the nortliern hemisphere rotate clockwise, assuming the 

 observer in front of the advancing organism, and the negatively photo- 

 tactic forms counter-clockwise, while in the southern hemisphere there 

 are reverse conditions. The apparent exceptions thus far noted have 

 been found closely allied to northern forms, and may have been intro- 

 duced subsequent to the origin of the southern forms. Evidence is 

 accumulating that this characteristic has been gradually impressed upon 

 the organisms through the rotation of the earth and the apparent path 

 of the sun from east to west. Natural selection, electrical conditions, 

 and other theories do not explain the phenomenon. Experimental 

 attempts to reverse, or to diminish the rapidity of the rotation of the 

 organisms have failed. The author suggests the need of studying the 

 behaviour of micro-organisms near the equator, as well as in the southern 

 hemisphere. E. S. G. 



