CHAP, xciii EVERGREEN DICOTYLOUS FOREST 339 



SUBTROPICAL RAIN-FOREST 



It has already been pointed out that the farther north one goes ni 

 Patagonian forest the more numerous do species become. Lianes, elaborate 

 epiphytes, and bamboos increase in numbers, and antarctic forest gives 

 way to subtropical rain-forest. In Chilian rain-forest species of Notho- 

 fagus still occur, but they are supplemented by numerous other species, 

 including Laurelia sempervirens, Drimys chilensis, Persea Lingue, and 

 Podocarpus nubigena. Underwood is abundant. Among epiphytes, 

 beside mosses and ferns, two Gesneraceae, Sarmienta repens and Mitraria 

 coccinea, also two species of Luzuriaga are common. In contrast with 

 tropical rain-forest the leaves of most of the trees are upwardly directed 

 and coriaceous, while ' drip-tips ' are rare.^ In rain-forest, on Juan Fer- 

 nandez, according to Johow,^ the trees have coriaceous or membranous 

 leaves devoid of ' drip-tips ' ; lianes are rare ; epiphytic ferns abound, 

 and in the underwood many tree-ferns grow. 



Fern-forest. Tree-ferns are dependent upon a humid atmosphere ; 

 they are indicative of an atmosphere continuously saturated with aqueous 

 vapour, and of a uniform climate. Forests in New Zealand, Australia, 

 and Tasmania, are rich in tree-ferns. In fact, these together with other 

 ferns and thin-leaved herbs may form the main mass of the vegetation.^ 

 jOn several of the more raised West Indian islands, for instance on 

 I Jamaica, which is extraordinarily rich in ferns, one finds on the mountains 

 }at a certain altitude, namely, in the cloud-belt, a vegetation that may 

 ibe termed fern-forest and includes such forms as Cyathea and Alsophila ; 

 jthis possibly gives us a blurred picture of one of the most ancient types 

 of vegetation. 



Tree-ferns are often very abundant in subtropical rain-forest that 

 occurs at a certain altitude on tropical mountains, where it replaces 

 tropical rain-forest. 



Subtropical rain-forest not only occurs in the subtropical places 



^already mentioned where rain falls throughout the year, but it is also 



met with both on mountains within the tropical zone, where at a certain 



iltitude it gives way to tropical rain-forest, and also in regions where the 



^vinter is more or less rainless although the whole rainfall is large in 



imount. These latter regions are found on the eastern sides of all conti- 



lents, namely in the United States, south Brazil, eastern South Africa, 



ast Australia to Tasmania, south China, and south Japan. In these 



'gions, as Schimper* has pointed out, subtropical rain-forest prevails 



vhere the annual rainfall is great ; whereas savannah-forest or savannah 



)ixupies drier country. In such places rain-forest may approach tropical 



rest in luxuriance.^ 



1)1 



TROPICAL RAIN-FOREST 



Encircling the Earth in equatorial countries there is a belt of forest 

 f which one thinks upon hearing the expression ' primeval forest '. 

 ^ -primeval forest is virgin forest that has preserved its original character 



' Philippi, 1858; Neger, 1897 a and fc, iqci. * Johow, 1896. 



' Consult Hochstetter, 1863; Tcnison-Woods, 1874; Cockayne, 1908; Dicls, 



(896, 1905. * Schimpcr, 1898. ' Kcin, 1881; Mayr, 1890. 



Z 2 



