156 APPENDIX. 



mahogany and india-rubber. The central zone is composed of grassy savanas, on which 

 cattle, mules, and horses are bred ; while the western zone, skirting the Pacific, possesses 

 a more diversified vegetation, and is an exceedingly fertile country, where all the 

 cultivated plants of the tropics thrive admirably. 



Costa Rica. 



This has an area of about 25,000 square miles, or about half that of England ; and 

 the mountain-chain, which is broken by the Eio San Juan and the Lake of Nicaragua, 

 again rises much higher than in Nicaragua, culminating in the Volcan de Irazu, which 

 is 11,500 feet high. Costa Rica has been much more fully explored botanically than 

 Nicaragua, chiefly by (Ersted, whose extensive collections have, however, only been 

 partly published and distributed ; hence the numerous blanks and low numbers in the 

 Geographical Table some pages further on. Nevertheless we are able to record upwards 

 of 1200 species of vascular plants. 



(Ersted ascended and botanized nearly all the volcanos from Chiriqui to El Viejo ; 

 and he described those of Costa Rica in his unfinished work ' L'Amerique Centrale,' 

 from which we obtain the following particulars : — 



The Volcan de los Votos is situated on the north of the town of Alajuela, and 

 rises to a height of 8000 feet by such a gentle slope that it can be ascended on 

 horseback. Its base is occupied by pasture-land and fields of maize, and the forests 

 only begin at altitudes of 5000 to 6000 feet. They are composed of Cedrela, Myrtacece, 

 Laurinece, Melastomacece, &c, and in the underwood grow various species of Chamce- 

 dorea, Ardisia, such Rubiacese as Psychotria hebeclada and Hamelia patens, and of 

 Composite, Verbesina microcephala, At about 7000 feet oaks predominate, and a 

 species of Podocarpus * with narrow leaves was found. The summit of the volcano 

 forms an undulating ridge from two to three miles in width, on the east of which rises 

 a little dome-shaped peak some few hundred feet high. The oaks there are very 

 stunted, and are mingled with a few shrubs such as Vaccinium consanguineum and Coma- 

 rostaphylis rubescens. The crater is situated on the north side, about 1000 feet below 

 the summit ; and in the centre is a small lake, the water of which contains sulphuric 

 acid, and emits air-bubbles and jets of vapour. Among the volcanic ashes scattered 

 about are found small pieces of native sulphur, which must have been much more 

 abundant there formerly, for the crater was frequently explored by collectors of sulphur. 

 Apparently the volcano is not quite extinct, for in 1834 a considerable eruption, accom- 

 panied by subterranean rumblings, took place, and cinders were thrown to a distance of 

 thirty miles. (Ersted visited its southern slopes in May 1847, and Dr. von Frantzius 

 also explored the crater in March 1860. (Peterm. Mitth. 1861.) 



The Volcan de Barba is separated from Los Votos by the Dezengano valley, and 



* This is the only evidence we have of this genus being represented north of the Isthmus of Panama. 



