OF PLANTS AND ANIMALS. 349 



is given not so much by the greater number of the spe- 

 cies which constitute one or two natural families, as by 

 the far more complicated relations which result from the 

 coexistence of a great number of families, and the relative 

 proportions of their respective species. Doubtless the gra- 

 minese and the cyperacese predominate in the prairies and 

 the steppes, as do coniferse, cupuliferse, and betulinse, in our 

 northern forests ; but this predominance of certain forms is 

 only apparent, produced by the particular aspect given 

 by the social plants. The north of Europe, and the zone 

 of Siberia which is situated to the north of the Altai, 

 are not more deserving of the title of regions of graminese or 

 of coniferse, than are the vast llanos of South America, or the 

 pine forests of Mexico. It is by the association of forms 

 which may partially replace each other, and by their relative 

 abundance and their groupings, that the vegetation of a 

 country produces its impression of luxuriance and variety, 



or of poverty and uniformity 







In this brief and fragmentary consideration of the 

 phenomena of organisation, I have ascended from the 

 simplest cell, ( 431 ) or -as it were the first manifestation 

 of life, progressively to higher forms. ( Mucilaginous 

 granules produce by their juxtaposition a cytoblast of 

 definite for LI, around which a vesicular membrane forms 

 a closed cell /' and this first germ of organisation is 

 either occasioned by a pre-existing cell, ( 43 ' 2 ) so that 

 cell produces cell, or the origin and evolution of the 

 cell is concealed in the obscurity of a chemical process, 

 analogous to the fermentation which produces the fungus in 

 yeast. It is not, however, the province of this work to do 



