350 COSMOS. 



the north of Asia as far as the latitudes of BerHii and Ham- 

 burg, a fact of which Ehrenberg and myself have; spoken in 

 other works.* 



The grouping 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 j ustify us in marking the geographical 

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

 lidaginse, of the Labiatse, or the Scitaminese. 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 Coniferee, Cupuliferae, and BetulineaB 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 GramineEe 

 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 cellf — the first mani- 

 festation of life — progressively to higher structures. " The 



* Ehrenberg, in the Annales des Sciences Naturelles, t. xxi., p. 387 

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



t Schleiden, Ueber die Enhvicklungsiceise der Pfianzenzellen, in Miil 

 ler's Archiv fur Anatomic und Physiologic, 1838, s. 137-176; also his 

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

 11. Schwann, Mikroscopische Untersnchungcn ubcr die Uehereinstim- 

 mting in der Struktur und dem Wachsthiim der Thiere und PJlanze?i, 

 1839, s. 45, 220. Compare also, on similar propagation, .Toh. Miillei- 

 Physiologic des Mcnschcn, 1840 th. ii., s. 614. 



