BOOKS AND CURRENT LITERATI! !. 169 



a clear account of the physiognomy of the forest, its ecological char- 

 acteristics and a classification of the vegetal ion according to distinctions 

 in habitats, such differences arising from position with regard to sun 

 and the prevailing wind, the highly dissected erosion topography and 

 altitude. Work of this kind is considered by Warming as not difficult, 

 and in comparison with some of the problems presented by plant 

 ecology which seem almost impossible to solve this is true enough, 

 but it is nevertheless far from an easy matter to paint an accurate 

 word-picture of a complicated closed association or to properly appreci- 

 ate and keep in their proper place the facts of observation when quite 

 minor distinctions may be of crucial importance. Above all, any 

 account of a plant formation loses half its value if it cannot be readily 

 used for purposes of comparison with related formations in other 

 regions. In this latter regard the author has succeeded in no small 

 degree, so that it is quite easy for one acquainted with a Xew Zealand 

 rain-forest to see wherein lie its resemblances to that of montane 

 Jamaica or its differences therefrom. 



The vegetation of ravines and ridges presents in a most striking- 

 manner the effects of erosion topography, that of the former being 

 strongly hygrophilous and of the latter almost xerophilous. So, too, 

 in certain New Zealand forests a ravine will contain hygrophilous 

 rain-forest and the ridge subxerophilous Noihofagus Solanderi forest, 

 this an altogether different formation. 



Epiphytes are a most important group in this Jamaican forest, every 

 type being represented, but on the other hand lianes, so much in evi- 

 dence in New Zealand, are not numerous. The epiphytes show a zonal 

 distribution in harmony with the moisture conditions, so that the 

 most hj'grophilous occupy positions near the ground, midway come 

 those that can tolerate an occasional scarcity of water, while in the 

 forest roof xerophytes flourish. These latter differ from those of a sim- 

 ilar station in New Zealand in that there is only one large plant, Cara- 

 guata sintenesii (Bromeliaceae), whereas in New Zealand this specie's 

 is represented by the epharmonically similar Astelia Solandri (Liliaceae), 

 while various spreading shrubs several feet in height are also present. 

 Possibly the most remarkable fact about these epiphytes is the physio- 

 logical capachy of certain Hymenophyllaceae to tide over considerable 

 periods of drought, whereas others of apparently identical structure 

 die rapidly in the absence of sufficient water. 



From the standpoint of general ecology, the concluding portion of 

 the book is of especial moment, dealing as it dot's with the transpiration 



