ANNOTATIONS AND ADDITIONS. 355 



sagittis superjici nequeant." (Humboldt, de distributione geogr. 

 Plantarum, pp. 178 and 213.) I find the first description of tree- 

 ferns in Oviedo's Historia de las Indias, 1535, fol. xc. This expe- 

 rienced traveller, who had been placed by Ferdinand the Catholic as 

 director of the gold-washings in Hayti, says : " Among the many 

 ferns there are some which I reckon among trees, for they are as 

 thick and as tall as pines (Helechos que yo cuento por arboles, tan 

 gruesos como grandes pinos y muy altos). They grow chiefly in the 

 mountains where there is much water/' The height is exaggerated. 

 In the dense forests round Caripe, even our Cyathea speciosa only 

 attains a height of 30 to 35 (32 to 37 English) feet; and an excel- 

 lent observer, Ernst Dieffenbach, in the northernmost of the three 

 islands of New Zealand, saw no stems of Cyathea dealbata of more 

 than 40 (42$ English) feet in height. In the Cyathea speciosa and 

 the Miniscium of the Chaymas missions we observed, in the midst 

 of the shadiest primeval forest, in very luxuriantly growing indivi- 

 duals, the scaly stems covered with a shining carbonaceous powder. 

 It seemed like a singular decomposition of the fibrous parts of the 

 old frond stalks. (Humboldt, Rel. hist. t. i. p. 437.) 



Between the tropics, where, on the declivities of the Cordilleras, 

 climates are placed successively in stages one above another, the 

 proper zone of the tree-ferns is between three and five thousand 

 feet (about 3200 and 5330 English) above the level of the sea. In 

 South America and in the Mexican highlands they seldom descend 

 lower towards the plains than 1200 (about 1280 Eng.) feet. The 

 mean temperature of this happy zone falls between 17 and 14. 5 

 Reaumur (70.2 and 64.6 Fahr.). This region enters the lowest 

 stratum of clouds, or that which floats next above the sea and the 

 plains; and hence, besides great equality of temperature, it also 

 enjoys uninterruptedly a high degree of humidity. (Robert Brown, 

 in Appendix to Expedition to Congo, p. 423.) The inhabitants, 

 who are of Spanish descent, call tlu> zone " tierra templada de los 

 helechos." The Arabic word for fern is feledschun, f being changed 

 into lij in helechos, according to the Spanish custom ; perhaps the 

 Arabic feledschun is connected with " faladscha," t( it divides ;" , in 

 allusion to the finely divided margins of fern leaves or fronds. (Abu 



