CURRENT LITERATURE 
BOOK REVIEWS 
A montane rain-forest 
As a result of several Mb to Jamaica, affording in all about 11 months’ 
residence upon the island, SHrevE' has contributed a study of a tropical 
rain-forest that is Narticnuties Jaabls since it represents practically the first 
attempt to determine quantitatively the factors concerned in the production 
of such vegetation. The forest investigated covers the Blue Mountains above 
an altitude of 1372 meters. T idge, having an altitude of 1500-2265 
meters, runs lengthwise of the island | therefore, is nearly at right angles 
to the direction of the trade winds. northern or windward side is fog- 
covered for 70 per cent of daylight hours ciel 9 months of the year and for 
30 per cent of daylight hours during the remaining months, while the rainfall 
approximates 425 cm. annually. The southern slope is drier, with less than 
half the amount of fog, and with an annual precipitation of about 265 cm. A 
further indication of the humidity is to be found in the evaporation measure- 
ments upon the leeward slope, giving maximum and minimum daily average 
losses of 17.9 cc. and 1.8 cc. (compared with approximately 45 cc. and ro cc. 
respectively for the Chicago region) as shown by the standard atmometer placed 
in the open, with half of these amounts for the forests of the ravines. These 
low amounts seem to be four or five times as great as for corresponding situa- 
tions upon the more humid northern slopes. 
Temperature has an annual range of 23° C., with the monthly mean from 
15° to 17° C., the maximum seldom exceeding 22°C. or the minimum 7 
while frosts are unknown. Detailed temperature si reas data for 
limited periods, as well as soil temperature records, are 
The mountain soil is very subject to erosion, ad this ‘Yustability may 
account, in part, for the absence of large trees; still, the forest is very con- 
tinuous, reaching its best development, however, in ravines, where trees 20 
meters in height are seen, with tru cm. in diameter in such species 
Solanum punctulatum and Gilibertia arborea. There seems to be no per 
complexity of floristic composition, the forest resembling in this respect temper- 
ate forests rather than those of tropical lowlands. This is indicated by the 
fact that Clethra occidentalis, Vaccinium meridionale, and Podocarpus Urbanii 
form about 50 per cent of the stand, and that an additional 35 per cent is made 
* SHREVE, Forrest, A montane rain-forest. A contribution to the physiological 
plant geography of Jamaica. Washington. 8vo. pp. 110. pls. 29. figs. 18. Carnegie 
Institution of Washington. Publication 199. 1914. $1.50. 
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