472 ZONES AND REGIONS [Pt. Ill, Sect. II 



the Cordilleras in North Argentina (Oran,Tucuman), the scanty rain-forests 

 of Natal, and possibly the somewhat different forests of Queensland and 

 New South Wales. It is difficult to draw the line between these forests 

 and the much more peculiar temperate rain-forests that will be subsequently 

 described ; such subtropical rain-forests frequently form a connecting link 

 between these temperate rain-forests and tropical rain-forests. 



The tropical rain-forest of the Brazilian coast near Santa Catharina at about 27 S. 

 appeared to me no less luxuriant and rich in forms, no less distinguished by the char- 

 acteristic oecological forms of the tropical forest, than the forests of Rio de Janeiro, 

 or those of Trinidad (n° N.). According to Ihering it is not until Rio Grande do Sul 

 is reached that there is a considerable reduction in the number of tropical forms asso- 

 ciated with the advent of new non-tropical ones, while simultaneously the tropical 

 aspect becomes lost owing to the disappearance of lianes and epiphytes. This forest 

 attains its southerly limit between 31 and 32° S. on the last slopes of the Serra dos 

 Taypes. 



The tropical forest of Bolivia, like that of Brazil, extends beyond the tropic of 

 Capricorn, becoming gradually poorer in type but enriched by temperate forms; 

 it, however, terminates in Tucuman, between 27 and 28 S. The impoverishment 

 of the type that occurs here is in particular exhibited in the reduction of the 

 diversity and dimensions of the woody lianes and the phanerogamous epiphytes, 

 which still are in Tucuman represented by a few orchids (Oncidium), as well as by 

 a few species of Rhipsalis and Peperomia and the dominant Bromeliaceae. In 

 comparison with the true temperate rain-forest, which will be subsequently de- 

 scribed, the trees grow more profusely mixed and attain large dimensions. A rich, 

 partly small-leaved and partly large-leaved underwood of Dicotyledones — tree- 

 ferns and bamboos are absent — more or less completely fills up the intervals 

 between them. 



The finest trees in the rain-forest of Tucuman, according to Lorentz, are : 

 Machaerium fertile (attaining a height of about 150 feet), Nectandra porphyria, Juglans 

 nigra, Linn., var. boliviana, DC, Cupania uruguensis and C. vernalis, Cedrela brasi- 

 liensis, var. australis, species of Acacia, Eugenia Mato and E. uniflora, Myrsine 

 floribunda and M. marginata, Chorisia insignis (a bombaceous tree with swollen 

 spiny stems), Pentapanax sp. ; small trees are among others Terminalia sp. (lanza 

 amarilla), Ruprechtia excelsa, Schmidelia edulis, Achatocarpus nigricans, Erythro- 

 xylum ovatum, Randia pubescens, Kageneckia amygdalifolia, various Solanaceae 

 such as Iochroma arborea, Solanum verbascifolium, S. pulchrum. 



Among the humbler, more or less shrubby woody plants, Lorentz distinguishes 

 some hard-wooded species, that sometimes become arborescent and have stiffer and 

 smaller leaves, such as CeltisTola, C. acuminata, Acacia tucumanensis, all three spiny 

 plants and more like lianes, Enkea Sieberi, Pisonia hirtella, Abutilon niveum, from 

 others that are lower in stature, less woody and have broad leaves, such as Phyto- 

 lacca bogotensis, Celosia major, Chamissoa celosioides, Acalypha cordifolia, Phenax 

 urticifolius, Boehmeria caudata, some Solanaceae. 



The largest lianes are bignoniaceous. Besides these there are climbing in the 

 forest various Leguminosae, such as Canavalia gladiata, Desmodium adscendens, 



