452 Floristik, Geographie, S5'steiriatik etc. 



stanti. Studio biologica e fitogeografico. (Publica- 

 zione 54 dell'Ufficio Idrografico del R. Magistrat© alle Acque. 

 Venezia, Officine Grafiche Carlo Ferrari. XVI. 348 pp. 75 tavole. 

 1913.) 



Contribution ä la connaissance de la Vegetation vasculaire de la 

 Lagune de Venise; consideree aux points de vue geographique et 

 ecologique; l'auteur a cultive les formes les plus caracteristiques, 

 pour en mieux suivre le cycle de developpement; les variations, le 

 polymorphisme. 



Sommaire: I. Etat actuel des connaissances sur la Flore de la 

 Lagune de Venise et sur les caracteristiques biologiques et geo- 

 grafiques; II. Apergu sur les conditions du milieu; III. Caracteres du 

 paysage botanique et des associations floristiques; IV. Types biolo- 

 giques en rapport avec les facteurs edaphiques et climatiques; V. 

 buree de la vie et ses variations; VI. Taille et ses variations; ^'11. 

 Phenomenes periodiques et leurs manifestations principales; VIII 

 Adaptations contre la mobilite des sables du littoral; IX. Adapta- 

 tions contre les saisons defavorables; X. Adaptations contre le de- 

 faut d'eau, particulierement dans la saison seche; XI. Apercu sur la 

 constance et la variabilite des caracteres. Polymorphisme et ses 

 manifestations; XII. Origine, histoire du developpement, affinite de 

 la flore de la Lagune et du littoral de Venise; XIII. Catalogue syste- 

 matique des plantes vasculaires; XIV. Especes ä exclure ou con- 

 firmer; XV. Bibliographie. C. Bonaventura (Firenzei. 



Bhide, R. K., Tvv^o more species of GramUieae fr o m B o m 

 bay. (Journ. and Proc. As. Soc. Beng. VIII. 7—8. p. 311—314. 

 2 pl. 1912.) 



The two new species described are Chloris quinquesetica and 

 Sporoholus scahrifoliits. W. G. Craib (Kev^r). 



Blackman, V. H., The Wilting Coefficient of the Soil. 

 (Jour. of Ecology II. p. 43—50. 1914.) 



A critical review of recent investigations, especialh'- v^rith refe- 

 rence to the indirect methods of Observation employed because of 

 lack of exact knowledge of the physical processes concerned in 

 root-absorption. The numerous factors involved in the investigation 

 of amount of available soil-water are indicated. The work of Briggs 

 and Shantz (1912) is carefuUy compared with that of Caldv^rell 

 (1913), and it is suggested that the partial agreement of the results 

 is mainly duc to a low rate of transpiration induced in a moist 

 environment; under these conditions permanent wilting is indepen- 

 dent of external conditions, and is mainly determined by the phy- 

 sical condition of the soil. The Utility of the method in the field 

 with its Wide ränge of environmental variations is therefore doubt- 

 ful. The relation of the wilting coefficient to different types of soil 

 is also considered, mainly with reference to the investigations of 

 Briggs, Mc Lane, and Shantz in America, and of Crump in 

 England. The review throughout is extremely Condensed, and does 

 not lend itself to further snmmary, hence the original must be 

 consulted for fuUer information. W. G. Smith. 



