640 EXPEBIMENT STATION RECORD. 



was partially protected against air currents a differential temperature of 10.31° 

 was obtained. Even diffuse ligbt according to its briglitness will increase the 

 leaf temperature from 0.5 to 2°. The average differential temperature for Feb- 

 ruary, the coldest month of the year, based on some 650 readings talien between 

 the hours of 8 a. m. and 3 p. m. was 3.06°. 



Although these differential temperatures are considerably less than tho.se ob- 

 taine<l by previous investigators for broad leaves under summer and tropical 

 insolation (he differences are believed to be of sufficient magnitude to become an 

 important factor in photosynthesis. More or less starch was found in various 

 conifers examined during the winter although no conclusive evidence of starch 

 formation was observed after December 13. This result, it is suggested, merely 

 indicates that photosynthesis was not sufficiently active under the conditions 

 that obtained during January and February to result in the production of starch 

 in the leaf. Carbohydrates may have been formed and used or translocated as 

 fast as formed. 



The literature of the subject is reviewed under the general headings of the 

 internal temperature of foliage leaves, photosynthesis and low temperatures, 

 and accumulation of reserve food material by evergreen trees in winter. 



A bibliography of consulted literature is appended. 



Beport on forest administration in Burma for the year 1912—13, C. G. 

 Rogers (Rpt. Forest Admin. Burma, 1912-13, pp. 111+4+149). — A progress 

 report on the administration of the state forests in Burma, including a financial 

 statement for the year 1912-13. The important data relative to alterations in 

 forest areas, forest surveys, working plans, forest protection, silvicultural opera- 

 tions, miscellaneous work, yields in major and minor forest products, revenues, 

 expenditures, etc., are appended in tabular form. 



Annual progress report on forest administration in the Presidency of 

 Beng'al for the year 1912-13, C. E. Muriel (Ann. Rpt. Forest Admin. Bengal, 

 1912-13, pp. Il+JfS+Jf, pi. 1). — A report similar to the above relative to the 

 administration of the state forests of Bengal for the year 1912-13. 



Progress report on forest administi'ation in the Northwest Frontier 

 Province for 1913—14, W. Mayes {Rpt. Forest Admin. Xorthicest Frontier 

 Prov., 1913-14, pp. 2+II+16+XXVI). — A report similar to the above relative 

 to the administration of the state forests of the Northwest Frontier Province 

 for the year 1913-14. 



DISEASES OF PLANTS. 



How saprophytic fungi may become parasites, G. Massee (Roy. Bot. Gard. 

 Kew, Bui. Mise. Inform. Xo. 5 (1914). PP- 190, 191). — A case is described in which 

 Clerodendron fallax at Kew had been attacked by Cladosporium epipfiyUum 

 under conditions favorable thereto. This had apparently started as a saprophyte 

 on the stalked peltate leaf glands excreting a nutritive liquid, and appeared to 

 have developed the parasitic habit within three weeks. It is thought that op- 

 portunities for habitually saprophytic but potentially parasitic fungi to change 

 their habit are numerous in nature, very slight changes of conditions being 

 sufficient to initiate the parasitic activity. 



Parasitism in Hymenochaete agglutinans, A. H. Graves (Mtjcologia, 6 

 (1914), ■S'o. 6, pp. 279-284: pi. 1). — This fungus is stated to be a facultative 

 parasite, having been found encircling, attacking, and killing Benzoin (rstivale 

 in contact with Alnus incana, which also it had apparently killed. It is 

 thought that the choking and consequent weakening effect of the encircling 

 fungus may have had something to do with its increase of activity in the host. 

 This is evidenced by the progressive diminution of growth of the latter above 



