388 SCIENCE PROGRESS 



Weather Review, U.S. Dept. Agric, xlviii, 1920, p. 215), has 

 investigated the chmatic conditions obtaining in a greenhouse. 

 These are expressed as rates of certain definite plant processes, 

 such as dry-weight production, leaf-area increase, rate of stem- 

 elongation, etc., the values thus obtained being expressed as 

 averages per week for each of the four-week periods. 



Amongst other recent papers dealing with plant-growth 

 the following may be mentioned : 



E. Reinau, " Die Horizonte der Wachstumsfaktoren als gestaltende 

 Ursache fiir die Wuchsformen der Pflanzen iiber und unter der Erde " ; 

 Angew. Bot., ii, 1920, p. 193 ; W. W. Garner and H. A. Allard, " Effect of 

 the Relative Length of Day and Night and other Factors of the Environment 

 on Growth and Reproduction in Plants," Jonrn. Agric. Res., xviii, 1920, 

 P- 553 ; F« G. Gregory, " Studies in the Energy Relations of Plants, I. The 

 Increase in Area of Leaves and Leaf Surface in Cucumis sativus,^^ Ann. Bot., 

 XXXV, 1921, p. 93 ; F. E. Lloyd, " Growth in Eriogonum nudum in Relation 

 to Environmental Factors," Trans. Roy. Can. Inst., xiii, 1921, p. 211. 



ZOOLOOY. By Prof. Chas. H. O'Donoghue, D.Sc, F.Z.S., Manitoba 

 University, Winnipeg, Canada. 



Protozoa.' — The papers include : 



Bhatia, " Notes on Fresh-water Ciliate Protozoa of India " {Trans. Roy. 

 Micro. Soc, pt. 3, 1920) ; Hegner, " Measurements of Trypanosoma diemyctyli 

 from Different Hosts and their Relation to Specific Identification, Heredity 

 and Environment " {Journ. Parasit., vol. vii, March 1921) ; Kudo, " Micro- 

 sporidia Parasitic in Copepods " (ibid., March 1921) ; and " Studies on 

 Microsporidia, with Special Reference to thbse Parasitic in Mosquitoes " 

 [Journ. Morph., vol. 35, No. i, March 1921) ; and Schrader, " A Microsporidian 

 occurring in the Smelt " {Journ. Paras., vol. vii, March 1921.) 



Invertebrata. — Stephenson has published a paper on " Con- 

 tributions to the Morphology, Classification and Zoogeography 

 of Indian Oligochaeta " {Proc. Zool. Soc., pt. i, March 1921) 

 which is subdivided as follows : I. The Affinities and Syste- 

 matic Position of the Genus Eudi chogaster Mchlsn., and some 

 Related Questions; II. On Polyphyly in the Oligochseta ; and 

 III. Some General Considerations on the Geographical Dis- 

 tribution of the Indian Oligochaeta. The sub-titles indicate 

 clearly the scope of the paper. The author concludes that 

 certain genera of the Oligochcetes are polyphyletic, and suggests 

 that, while phylogeny should of course form the basis of a natural 

 classification, until the former has been satisfactorily determined 

 it becomes almost impossible to avoid setting up polyphyletic 

 genera. In the last part the author goes into the question of 

 land bridges that have been postulated at various times, i.e. an 

 Indo-Australasian, an Indo-New-Zealand, and an Indo-African, 

 and so far as the earthworms are concerned he is inclined to 

 think that they are not necessary to explain the distribution. 



