350 COSMOS. 



tlie north of Asia as far as the latitudes of Berhn and Ham- 

 burg, a fact of which Ehrenherg and myself have spoken in 

 other works* 



The grov ping or association of different vegetable species, 

 to which we are accustomed to apply the term Floras, do not 

 appear to me, from what I have observed in different portions 

 of the earth's surface, to manifest such a predominance of in- 

 dividual families as to justify us in marking the geographical 

 distinctions between the regions of the Umbellatae, of the So- 

 lidaginsB, of the Labiatee, or the ScitaminesB. With reference 

 to this subject, my views differ from those of several of my 

 friends, who rank among the most distinguished of the bota- 

 nists of Germany. The character of the floras of the elevated 

 plateaux of Mexico, New Granada, and Quito, of European 

 Russia, and of Northern Asia, consists, in my opinion, not so 

 much in the relatively larger number of the species presented 

 by one or two natural families, as in the more complicated 

 relations of the coexistence of many families, and in the rela- 

 tive numerical value of their species. The Graminese and 

 the Cyperacese undoubtedly predominate in meadow lands 

 and steppes, as do ConifersB, Cupuliferee, and Betulineae in our 

 northern woods ; but this predominance of certain forms is 

 only apparent, and owing to the aspect imparted by the social 

 plants. The north of Europe, and that portion of Siberia 

 which is situated to the north of the Altai Mountains, have 

 no greater right to the appellation of a region of GraminesB 

 and Coniferse than have the boundless llanos between the 

 Orinoco and the mountain chain of Caraccas, or the pine for- 

 ests of Mexico. It is the coexistence of forms which may par- 

 tially replace each other, and their relative numbers and as- 

 sociation, which give rise Either to the general impression of 

 luxuriance and diversity, or of poverty and uniformity in the 

 contemplation of the vegetable world. *" 



In this fragmentary sketch of the phenomena of organiza- 

 tion, I have ascended from the simplest cellt — the first mani- 

 festation of life — progressively to higher structures. " The 



* Ehrenberg, iu the Annates des Sciences Naturelles, t. xxi., p. 387 

 412; Humboldt, Asie Centrale, t. i., p. 339-342, and t. iii., p. 96-101 



+ Schleiden, TJeber die Entwichlungsioeise der Pflanzenzellen, in MUl 

 lers Archiv fur Anatomic nnd Physiologic, 1838, s. 137-176; also hia 

 Grundzuge der wissenschaftlichen Botanik, th. i., s. 191, and th. ii., s 

 ir. Schwann, Mikroscopiscke Untersuchungen uber die Ucbercinstim- 

 mung in der Struktur und dem Wachsthum der Thiere nnd PJlanzen, 

 1839, 8. 45, 220. Coinpai^ also, on similar propagation, Joh. Mu'ler 

 Physiologic des Mcnschen, 1840 th. ii.. a, 614. 



