GEOGRAPHICAL SITUATION OF PLANTS. 207 



bold and graphic language, said,* " A practical botanist can 

 usually at the first glance distinguish the plants of Africa, Asia, 

 America, and the Alps ; but it is not easy to tell how he is able 

 to do this. There is a certain character of sullenness, gloom, 

 and obscurity in the plants of Africa ; something lofty and ele- 

 vated in those of Asia ; sweet and smiling in those of Ameri- 

 ca; while those of the Alps seem rigid and stinted." In in- 

 vestigating the geographical situation of the vegetable kingdom 

 we see the powerful effects of light and heat. Feeble in the 

 polar regions^ vegetation acquires strength as we approach to- 

 ward the equator^ where the light of the sun is vivid, and its 

 heat permanent and intense. At the termination of the land at 

 the Arctic Ocean there is one long, cold night, and one day of 

 warmth, in which vegetation is rapidly brought forward ; plants 

 in some cases germinate, blossom, perfect tht^ir seed, and die 

 within six weeks. Within the limit of perpetual snow the arc- 

 tic sailors have found large patches of the Palmella nivalli^ 

 red snow (of the algae tribe), the simplest of all the vegetable 

 race ; the plant consists but of 07ie cell^ containing a fluid. On 

 the Alps and Pyrenees it is found reddening the surface of the 

 snow, from w^hich it derives its support. A species of lichen 

 (the Gyrophora) was found, and used for food by Sir John 

 Franklin, within the arctic circle. After passing from the arc- 

 tic circle to the borders of the temperate zone, we find a few 

 species of plants, chiefly lichens^ 7nosses^ andferns^ also a few 

 shrubs and herries. Lapland is the only country within this 

 zone where any kind of grain can be raised. In those frozen 

 climates plants are low and stinted which in other situations 

 rise to a great higlit. The leech and willoiL\ the giants of those 

 regions, rise but a few inches above the surfece of the ground, 

 wdiile their stems lie hidden among the moss, as if wanting 

 strength to penetrate the soil. 



319. Humboldt divided the tenijyerate zone^ with respect to 

 productions, into three regions : the cold^ the temperate^ and 

 warm / in the cold region grain may be raised to advantage, 

 and herries grow in abundance. In the temperate region the 

 loine-grape., grain^ and fruits of many kinds are cultivated in 

 their greatest perfection. The warm region produces olives., 

 figs^ oranges.^ and lemons. The variety of plants in the torrid 

 zone is very great ; trees are more numerous in proportion to 

 other plants than in the temperate zones ; the same tribes 

 which are there slender and humble plants, here spread into 

 lofty trees many of which are adorned wdth large and beauti- 



* " Primo intuitu distin^uit sjcpius exercitatus botanicus plantas AfriciB, Asia-, America, Alpinm- 

 que, sell non facile dieerit ipse ex qua nota. Nescis qurc f'acies torva, sicca, obscuris Afris ; (|uae 

 Buperba exaltata AsiSiticis ; qute Iseta, glabra Americanis ; qux coarctata, indnra Alpinis." 



Plants of the frigid zone.— 319. Tennperate zone — Torrid zone. 



