I 



1920] EXPERIMENT STATION RECORD. 241 



FORESTRY. 



The oak hornboani woods of H«Ttf«»rdsliir<*, I-IV, E. J. SAT.iSRTnv 'f7o»r. 

 Ecology, -} (J'llti). Xu. 2, pp. HS-Ul, pis. 2, fif/x. r, ; 6 (I'JIS), No. 1, pp. lJ,-52, figs. 

 2). — This pajter is liasi'd chiefly upon detailed observations made (hiring the 

 past 5 years upon most of the more important woods in Hertfordsiure. In- 

 formation is given relative to the history and status of these woods, as well as 

 to tlieir elimatir, e<lai)lM(', and Iij,dit conditions and the existinj,' flora of both 

 iiiicopi)ic«'d and c(ti)pice(l woods. 



On tlie causes of failur*- of natural regeneration in British oakwoods, 

 A. S. Watt {.lour, luolog)/, 7 (/.''/,'»). .\o. S-^, pp. 17.3-20.7).— Results are given 

 of a study of natur:il regeneration in <lifTerent types of British oakwoods. 



The author found that, aside from the destruction to acorns i)y herbivorous 

 aidmal.s, ndldew was an important factor in producing fatal effects on oak 

 seedling.s, especially in sandy soils. There were generally no inherent difli- 

 culties to prevent natural regeneration in damp oakwood, hut in dry oakwood 

 and oak birch-heath associations the supply of light to the seed beds was greatly 

 (limiiiished by the presence of bracken and the vitality of the seedlings im- 

 paired, thus materially assisting the fungus in its fatal effects. 



The resin usufriK't of the pine, L. Schikhlingkr (Xntiinv. Ztschr. Forst n. 

 I.dtiilir.. n (ini!)). No. 10-12. pp. 2Si-365).—A contribution from the Muiuch 

 Forestry Experiment Station c(mii>rising a discussion of the factors governing 

 the formation and flow of resin, together with the results of experimental tap- 

 ping studies and practical recommendations for turpentining operations based on 

 these studies. 



Revision of the true mahoganies (Swietenia), S. F. Blakk {•lour. Wash. 

 Acad. Sci., 10 {V.Kin), No. 10, pp. 2S6-207, figs. 2).— A revision of the four pre- 

 viously determined species of Swietenia, together with a new species here de- 

 scribed and namc<l by the author as ,S. cirrhata n. sp. 



Studies in the ecology of tropical rain forest, with special reference to 

 the forests of South Brazil, R. C. McLean {./our. Ecology, 7 {1!)10), Nos. 1-2, 

 l>l>. 5-5J,, pi 1, figs. 22; 3-4, pp. 121-172, figs. iO).— The study here reported was 

 conducted with a view to measuring the factors of moisture and illumination in 

 the interior of the forests on the slopes of the hills and in the valleys around 

 about Rio do .Janeiro and southern Brazil, and to determine the influence of 

 these factors on the undergrowth plants, morphologically and otherwi.s<>. Tart 

 1 re|>orts studies dealing with the factor of- Inimidity and p.irt 2 with that of 

 illumination. Important facts brought out relative to the physiological status 

 t>f the undergrowth are i)resented in a general summary. A descii]itive ecology 

 of the fori'st and a bibliography are appended. 



Report of the division of forestry (H'or Dcpt. [U. S.], Ann. Rpf. Corcrnor 

 P. It., 19 (1919). pp. 701-70.3). — A brief statement of operations thus far con- 

 ducted by the Porto Rico Forest Service, which was created on November 

 22, 1917. 



Annual report on the forest administration in Ajmer-Merwara for the 

 I jear 1»1«-19, Sma.muhoo Datt .Ioshi {.Attn. Rpt. Forest Admin. Ajincr- 

 I Menrara, HUS-19, pp. .iO). — The usual report relative to the administration ami 

 management of the State forests of Ajmer-Merwara for the year 1018-19. I>ata 

 relative to alterations in forest areas, forest surveys, working plans, forest 

 protection and miscellaneous work, yields in major and minor forest products, 

 ii'venues, expenditures, etc., are appended in tabular form. 



The forests of Greece, .T. Masstas {Rcr. Eaux ct Forcfs, .77 {IHI9). Xo. II. pp. 

 2J7-2.'/7). — An account is given of the forests of Greece, with reference to their 



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