THE TOPMOST COUNTRY OF THE EARTH. S 2 7 



The great diversity of the chemical combinations that plants, in- 

 stead of applying for their proper growth, store up in their tissues as 

 a means of protection against the heat of the sun, the lower fungi, or 

 animals, is really astonishing. Even in the liverworts we meet differ- 

 ent substances neither the chemical nature nor the biological impor- 

 tance of which is clearly enough known. Among the ferns, only the 

 under-ground stems are endowed with substances of strong qualities. 

 Only single groups among the monocotyledonous plants, and of these 

 the leaves (Aracece) or the flowers (Mielanthacece, lilies) of which show 

 a higher organization, possess acrid poisons or alkaloids or aromatic 

 substances. Among the conifers and dicotyledonous plants the strong 

 substances are very widely diffused in the more enduring kinds. 



We have not considered the coloring-matters and odors of the 

 flowers and fruits in this sketch, for they do not serve for protection, 

 but to attract animals. 



It is worthy of remark that plants which produce particular sub- 

 stances may be naturalized in regions in which those substances are 

 not required by them. The labiates and rues, which originally be- 

 longed to hot climates, still produce ethereal oils in Northern and 

 Central Europe, although they no longer need protection against the 

 hot sun. Closer reflection on the facts we have set forth will show 

 that the real relation must be properly presented as a whole. 



Numerous observations, nevertheless, are still necessary in individ- 

 ual cases to make the true significance of each particular phenomenon 

 clear. Kosmos. 



4r++ 



THE TOPMOST COUNTKY OF THE EAETH. 



By LnsinsHABT G. KKEITLEE. 



THE name Thibet, as we call that highland, the natural isolation 

 of which gives it a unique position in the world, is not known 

 among the people who inhabit it. The Thibetans call their country 

 Bod, or Bod-yirl ; the inhabitants of the northern slopes near the great 

 desert call it Tungut ; the Chinese, Si-fan. The highland proper rises 

 in the form of a huge elongated segment of a circle from the adjacent 

 lowlands, and is formed by Nature herself, through the sharply denned 

 rocky precipices that inclose it on every side, into a separate part of 

 the world. The country is bordered on the south by the heaven-aspir- 

 ing crests of the Himalayan system, consisting of three nearly parallel 

 ranges, the southernmost of which forms the real roof of the Thibetan 

 highland. Impenetrable tropical woods rising from the fever-breeding 

 forest and swamp lands are met at a considerable height by the pine- 

 growths, the whole forming a wonderful panorama ; above these rise 



