Difference in the richness of languages as regards precise and definite words for characterizing natural phenomena, such as the state of vegetation and the forms of plants, the contour and grouping of clouds, the appearance of the earth’s surface, and the shape of mountains. Loss which languages sustain in such expressive words. The misinterpretation of a Spanish word has enlarged mountain-chains on maps, and created new ranges. PRIMEVAL FOREST. Frequent misuse of this term. Want of uniformity in the association of the arboral species is characteristic of the forests within the tropics. Causes of their imperviousness. The Climbing plants (_Lianes_) often form but a very inconsiderable portion of the underwood—pp. 191–196. Aspect of the Rio Apure in its lower course. Margin of the forest fenced like a garden by a low hedge of Sauso (_Hermesia_). The wild animals of the forest issue with their young through solitary gaps, to approach the river-side. Herds of large Capybaræ, or Cavies. Fresh-water dolphins—pp. 196–199. The cries of wild animals resound through the forest. Cause of the nocturnal noises—pp. 199–200. Contrast to the repose which reigns at noontide on very hot days within the tropics. Description of the rocky narrows of the Orinoco at the Baraguan. Buzzing and humming of insects; in every shrub, in the cracked bark of trees, in the perforated earth, furrowed by hymenopterous insects, life is audible and manifest—pp. 200–201. SCIENTIFIC ILLUSTRATIONS AND ADDITIONS pp. 202–203. Characteristic denominations of the surface of the earth (Steppes, Savannahs, Prairies, Deserts) in the Arabic and Persian. Richness of the dialects of Old Castile for designating the forms of mountains. Fresh-water rays and fresh-water dolphins. In the giant streams of both continents some organic sea-forms are repeated. American nocturnal apes with cat’s eyes; the tricoloured striped Douroucoali of the Cassiquiare—pp. 202–203. HYPSOMETRIC ADDENDA pp. 204–209. Pentland’s measurements in the eastern mountain-chain of Bolivia. Volcano of Aconcagua, according to Fitz-Roy and Darwin. Western mountain-chain of Bolivia—pp. 204–205. Mountain systems of North America. Rocky Mountains and snowy chain of California. Laguna de Timpanogos—pp. 205–207. Hypsometric profile of the Highland of Mexico as far as Santa Fé—pp. 207–209. IDEAS FOR A PHYSIOGNOMY OF PLANTS pp. 210–231. Universal profusion of life on the slopes of the highest mountain summits, in the ocean and in the atmosphere. Subterranean Flora. Siliceous-shelled polygastrica in masses of ice at the pole. Podurellæ in the ice tubules of the glaciers of the Alps; the glacier-flea (_Desoria glacialis_). Minute organisms of the dust fogs—pp. 210–213.