244 Physiologie. — Algae. 



Füller, G. D., Evaporation and the Stratification of Ve- 

 getation. (Botanical Gazette. LIV. p, 424—426. with 1 fig. Nov. 

 1912.) 



The study was made in an undisturbed climax, mesophytic, 

 beech-maple forest about 45 miles southeast of Chicago, near the 

 village of Otis. Ind. The results are platted graphically for three 

 different strata in the forest. He found, that if the average rate of 

 evaporation at the stations upon the forest floor be taken as unity, 

 the proportional evaporating power of the air in the three strata 

 will be found to be nearly 1.84:1.00:0.80 for the season- 



Harshberger. 



Gager, C. Stuart, Ingrowing Sprouts of Solanum tuberosum. 

 (Botanical Gazette. LIV. p. 515—523. l pl. 6 fig. Dec. 1912.) 



The author finds that ingrowing sprouts of the potato make 

 their way through the tissue of the tuber not by enzymatic digestion 

 of a Channel in the tissue, but by mechanical pressure which goes 

 with growth in length. The growth force is not sufficient to pierce 

 the skin. He found that new tubers were found on such ingrown 

 sprouts and he concludes, that their formation is a function of 

 external conditions plus the genotypical Constitution of the species. 



Harshberger. 



Ganong, W. F., The Living Plant: a Description and In- 

 terpretation of its Functions and Structure. (London: 

 Constable and Company. 478 pp. 178 fig. Price 15 sh. net. 1913.) 



This book is intended primarily for general readers, though 

 containing much that is of interest and value for the botanist and 

 especially for the teacher of the physiology of plants. The author 

 incorporates the results of recent research in plant physiology, and 

 gives a number ot original and ingenious diagrams and "schemes" 

 to illustrate the main processes in plant life and the various rela- 

 tions between the plant and its environment. F. Cavers. 



Henry, T. A., The Plant Alkaloids. (London: J. and A. Chur- 

 chill. VII. 466. Price 18 sh. net. 1913.) 



The author brings together the chief historical, chemical, phy- 

 sical and physiological facts known concerning the vegetable alka- 

 loids. These bodies are arranged in nine groups, one of these inclu- 

 ding "alkaloids of unknown Constitution." General questions — 

 such as the correlation of the chemical Constitution of alkaloids 

 with their action on the animal System, the mode of formation of 

 alkaloids in the plant, and their function in the plant — are only 

 dealt with briefly. F. Cavers. 



Blanchard, F. N,, Two new species of Stigonema. (Rhodora. 

 XV. p. 192—200. pl. 105. November 1913.) 



Folio wing the description of two new species of Stigonema (S. 

 anomalum Blanchard and 5. medium Blanchard), both from Che- 

 bacco Pond, Essex, Massachusetts, the writer discusses the 

 characters of these and related forms in a comparative way and 

 concludes that Hapalosiphon , Sirosiphon, and Fischerella are best 

 regarded as subgenera of Stigonema, Sirosiphon containing those 



