No. 2, June, 1921] ECOLOGY, PLANT GEOGRAPHY 137 



tively thick integument which is somewhat resistant to low temperatures of short duration 

 such as are common in the Arizona and adjacent deserts. A large range of resistance was 

 found in different species. — Geo. D. Fuller. 



V 



949, Wylie, R. B. Trimorphism of Pontederia. [Rev. of: Hazen, Tracy E. The 

 trimorphlsm and insect visitors of Pontederia. Mem. Torrey Bot. Club 17: 459-484, 1918 

 (seeBot.Absts. 1, Entry 830).] Bot. Gaz. 67:271-272. 1919. 



VEGETATION 



950, Fuller, George D. Distribution of Pinus Banksiana and Thuja occidentalis. 

 [Rev. of: Fernald, M. L. Lithological factors limiting the ranges of Pinus Banksiana and 

 Thuja occidentalis. Rhodora 21: 41-67. 1919 (see Bot. Absts. 4, Entry 283).] Bot. Gaz. 

 68: 149-150. 1919.— The reviewer feels that the author has criticized somewhat too severely 

 Hutchinson's theory as to the cause of the distribution of these two trees (see Bot. Absts. 

 4, Entry 190). It is felt that there is truth in both theories, and that they are not necessarily 



nharmonious with one another. — H. C. Cowles. 



951, Fuller, George D. Vegetation of Cape Breton. [Rev. of: Nichols, George E, 

 The vegetation of northern Cape Breton Island, Nova Scotia. Trans. Connecticut Acad. Arts 

 and Sci. 22: 249-467. 70 fig. 1918 (see Bot. Absts. 1, Entry 833).] Bot. Gaz. 67: 370-373, 

 1919, — "In its comprehensive character, its abundance of detail, and its notable contributions 

 to various phases of ecology, including the relationships between deciduous and coniferous 

 forests, the ecology of the sphagnums and of the development of raised bogs, this report 

 stands as one of the most notable of recent years." — //. C. Coirles. 



952, Fuller, George D. Heath and grassland. [Rev. of: Farrow, E. P, On the 

 ecology of the vegetation of Breckland. Ill, General effects of rabbits on the vegetation, IV. 

 Experiments mainly relating to the available water supply. V, Observations relating to com- 

 petition between plants. VI. Characteristic bare areas and sand hummocks. Jour. Ecol. 5: 

 1-18, 104-112, 15.>-172, 1917; 6: 144-152, 1918 (see Bot. Absts. 1, Entry 824).] Bot. Gaz. 

 67: 181-182, 1919. 



953, Hauman, Lucien. La vegetation des hautes Cordilleres de Mendoza (Republique 

 Argentine). [The vegetation of the high Cordilleras of Mendoza,] An. Soc. Cien. Argentina 

 86: 121-188, 225-348. 21 pL, 7 fig. 1918.— This article gives a rather detailed description of 

 a scanty alpine vegetation found on the high Andes between 31 and 37°S. latitude at elevations 

 from 2000 to 4200 meters. This region possesses many peaks exceeding 6000 m., the highest 

 and best known being Aconcagua with an altitude of 7020 m. These are snow capped and 

 possess a good development of glaciers, from which flow tortuous and variable streams. These 

 furnish almost the entire water supply for the sparse vegetation as the growing season in these 

 mountains is almost entirely without rain. The temperature records are imperfect but an 

 important factor is seen in the light frosts which are common throughout the growing season. 

 One station at 2700 m. gives an annual mean temperature of 6.5°C., with mean maximum of 

 13.4°C., and a mean minimum of 0.1°C. Humidity is at all times low while wind velocity is 

 decidedly high and constant. Precipitation as recorded at 2000 m, seems to be irregular and 

 variable, the annual amounts ranging from 20 to 69 cm., occurring principally in the colder 

 months in the form of snow. This deficiency of rainfall combined with other factors makes 

 the vegetation not only very scanty but limited to valleys and slopes which possess streams 

 or seepage water from the glaciers and snowfields. In the absence of mountain lakes aquatic 

 vegetation is scanty and anything like mountain meadows are limited to the stream edges and 

 small alluvial fans. Such grassy associations appear to closely resemble similar alpine areas 

 elsewhere. Related to the alpine meadows are the "high Andean oases" formed at 3200-3600 

 m. where at the foot of talus or morainal slopes some alluvial soil has accumulated. These 

 oases vary in size but rarely reach 100 m. in diameter. Thev are often dominated bv the 



