30 ECOLOGY, PLAXT GEOGRAPHY [Bot. Absts., Vol. IV, 



212. Btjrkill, I. H. Some notes on the pollination of flowers in the Botanic Gardens, 

 Singapore, and in other parts of the Malay Peninsula. Gardens' Bull. Straits Settlements 2: 

 165-176. 1919. — An account is given of observations on flowers visited by Xylocopa, Antho- 

 phora, Melipona, Vespidae, butterflies and moths, and sun-birds. — S. F. Trelease. 



213. Cannon, W. A. Root-growth of Prosopis velutina and Opuntia versicolor under con- 

 ditions of a small oxygen supply in the soil. Carnegie Inst. Washington Yearbook 16: 82-83. 

 Feb., 1918. — In Prosopis growth continued for some time in an atmosphere of 2.67 per cent 

 oxygen, but in Opuntia it stopped promptly. In an atmosphere of 4.56 per cent oxygen the 

 longer roots of Prosopis continued growth for five days while those of Opuntia ceased entirely 

 at the end of 48 hours. — Geo. D. Fuller. 



214. Cannon, W. A. Relation of the rate of root growth of Prosopis velutina to the temper- 

 ature of the soil. Carnegie Inst. Washington Yearbook 16: S2. Feb., 1918. — Growth in this 

 species occurred at temperatures ranging from 12°C. to 42°C. with an optimum at 34°C. The 

 rate of growth was also found to be correlated with the length of the root being greater in 

 roots less than 50 mm. in length. — Geo. D. Fuller. 



215. Cremata, Merlino. Plantas meliferas. [Melliferous plants.] Revist. Agric. Com. 

 y Trab. 2: 140-152. 10 fig. 1919. — A list of plants in Cuba visited by bees arranged alpha- 

 betically by families is given with notes on importance, time of flowering, and distribution. 

 — F. M. Blodgett. 



216. Denis, Marcel. Sur quelques thalles d'Aneura depourvus de chlorophylle. [On 

 certain thalli of Aneura devoid of chlorophyll.] Compt. Rend. Acad. Sci. Paris 168: 64-66. 

 2 fig. Jan., 1919. — While Aneura commonly harbors an endophytic fungus, comparable to 

 mycorhiza in vascular plants, the species here described has an unusual development of 

 endophytic fungi. Apparently as a result of this symbiosis, the liverwort is without chloro- 

 phyll and has a coralloid appearance, and thus appears to depend upon the fungus for its nour- 

 ishment. Comparison is made with the gametophyte of Lycopodium, which also may or may 

 not possess chlorophyll, depending on the species. [See Bot. Absts. 2, Entry 9S2; also rev. 

 by Magrou in Bull. Trimest. Soc. Mycol. France 35: 164. 1919.]— H. C. Cowles. 



217. Dosdall, Louise. Water requirement and adaptation in Equisetum. Plant World 

 22:1-13,29^41. 5 fig. 1919. — The current views of bog xerophyt ism are summarized. From 

 a study of the soil water requirements and transpiration of Equisetum fluviatile as compared 

 to Ranunculus sceleratus and Helianthus annuus, the author concludes that E. fluviatile is 

 not to be considered a xerophyte growing in xeroplvytic parts of bogs because of low absorptive 

 powers, but is a true hydrophyte, possessing only superficial xeromorphy. It is thought that 

 the superficial xerophytic appearance of Equisetum was acquired in some cold, arid period of 

 geological history, and that the structures are extremely stable. Adaptation to hydrophytic 

 conditions has come about through the development of air spaces, diaphragms, and perman- 

 ently open stomata, without modification of the external xeromorphy. Transpiration is 

 twice as rapid per unit area in E. fluviatile as in the sunflower which is noted for its rapid use 

 of water. It therefore belongs in the hydrarch succession, to the reed swamp or sedge-swamp 

 association. E. hyemalc and E. arvense are more mesophytic. High transpiratory activity 

 of E. fluviatile is correlated with low photosynthetic efficiency as compared to Phaseolus 

 vulgaris and Ranunculus. — Chas. A. Shull. 



218. Farr, C. H. The ferns of the rain-forest. Sci. Monthly 9: 19-31. SO fig. 1919. — 

 Tree ferns grow in the most evenly tempered climates and cannot endure strong winds nor 

 direct sunlight. The mountain forest of the tropics furnishes ideal conditions for them. In 

 the old world tree ferns are distributed between 47 degrees south and 32 degrees north lati- 

 tude. They are most abundant in Australia and the Pacific Islands, although numerous in 

 Ceylon, Java and New Zealand. In the western hemisphere, their distribution is from about 

 44 degrees south to 25 degrees north latitude. The Hawaiian Islands, the Antilles, the Andes, 



