106 



ORGANIC LIFE. 



connexion with the members of the vegetable 

 kingdom. Agricultural nations increase arti- 

 ficially the domain of various social plants, and 

 so increase the aspect of uniformity presented 

 by nature in several districts of the temperate 

 and northern zones ; they also root out and de- 

 stroy various wild-growing plants, and unin- 

 tentionally propagate others that follow man in 

 his wanderings. The luxuriant zone of the 

 tropical world resists more powerfully this for- 

 cible metamorphosis of creation. 



Observers who have perambulated extensive 

 districts of country in short intervals of time, 

 who have ascended mountain ranges in which 

 the climates lie stratified one over another, 

 must soon have been awakened to the regular 

 distribution of vegetable forms. They collect- 

 ed the raw material of a science whose name 

 was not yet pronounced. The same zones or 

 regions of plants which Cardinal Bembo(3^'), in 

 the 1 6th century, when yet a youth, described as 

 occurring on the slopes of Etna, were found re- 

 peated on Mount Ararat, by Tournefort, who 

 acutely compared the Alpine floras with the 

 floras of plains under different latitudes ; and 

 who first remarked that the elevation of the 

 ground above the level of the sea in mountain- 

 ous districts influences the distribution of plants 

 in the same way as distance from the pole in 

 plains. Menzel, in an unedited Flora of Japan, 

 incidentally used the expression Geography of 

 Plants. This phrase again recurs in the fan- 

 tastic but pleasant '* Studies of Nature" of Ber- 

 nardin de St. Pierre. But the scientific treat- 

 ment of the subject commenced wiien the dis- 

 tribution of plants was viewed in close connex 

 ion with the doctrine of the distribution of heat 

 over the surface of the earth ; when plants 

 were arranged into natural orders, and it was 

 thus made possible to distinguish numerically 

 the particular forms which increase or diminish 

 from the equator towards the poles, to per- 

 ceive, in the different regions of the earth, in 

 what numerical relationship each family stands 

 to the whole of the mass of phanerogamous 

 vegetables which are there indigenous. It is 

 one of the fortunate events in my life, that at 

 the time when I was giving my attention al- 

 most exclusively to botany, my studies should 

 have been directed to the subject of inquiry 

 just mentioned, by the spectacle of nature on 

 the grandest scale, and offering the strongest 

 contrasts in respect of climate. 



The geographical distribution of animal 

 forms, upon which Buffon first advanced gen- 

 eral, and, for the major part, very accurate 

 views, has in recent times had great assist- 

 ance from the progress of vegetable geography. 

 The curvatures of the isothermal, and particu- 

 larly of the isochimenal lines, are displayed in 

 the limits which certain species of plants, and 

 of animals that do not roam far towards the 

 north or towards the tops of snow-covered 

 mountains, seldom exceed. The Elk, e. g., 

 lives in the Peninsula of Scandinavia, almost 

 ten degrees farther to the north than in the in- 

 terior of Siberia, where the lines of like win- 

 ter temperature are so remarkably concave. 

 Plants wander or migrate in the egg, in the 

 seed. The seeds of many species are provi- 

 ded with peculiar organs for far journeys 

 through the air. Once rooted, they are more 



dependent on the soil and the temperature of 

 the atmosphere which surrounds them. Ani- 

 mals widen at will the circle of their presence 

 from the equator towards the pole, and partic- 

 ularly in regions where the isotheral lines arch 

 out towards the north, where hot summers suc- 

 ceed the severest winters : royal tigers, which 

 do not differ from those of India, roam every 

 summer in Northern Asia to the latitudes of 

 Berlin and Hamburg, as Ehrenberg and I have 

 shown in another place(*''°). 



The groups or associations of vegetable spe- 

 cies which we are accustomed to designate 

 Flor^ (spheres or domains of vegetation), 

 appear to me, from what I have seen o'' the 

 earth, by no means to reveal the prevalence of 

 individual families to such an extent as au- 

 thorizes us to establish geographical regions of 

 the Umbellatae, Solidagineae, Labiatae, or Sci- 

 tamineae. My particular views differ in this re- 

 spect from those of several of my friends among 

 the most distinguished botanists of Germany. 

 The character of the Floras in the high lands 

 of Mexico, New Granada, Quito, European 

 Russia, and Northern Asia, consists, as I be- 

 lieve, not in the relatively larger number of 

 species which one or two natural families ex- 

 hibit, but rather in the much more complex re- 

 lations of the aggregate life of many families, 

 and the relative numerical value of their spe- 

 cies. In meadow and steppe districts Gram- 

 ineffi and Cyperaceae are the prevailing fami- 

 lies ; in our northern woods we meet especial- 

 ly with Coniferae, Cupuliferae, and Betulineae ; 

 but this prevalence of form is only apparent, 

 and deceptive by reason of the mass of the So- 

 cial plants arresting the eye. The north of 

 Europe, and Siberia in the zone northward 

 from the Altai, no more deserve the title of a 

 realm of grasses or cone-bearing trees, than 

 the endles Llanos between the Orinoco and 

 the mountain chain of Caraccas or the pine 

 forests of Mexico. In the associated life of 

 the vegetable forms which partly replace one 

 another, in their relative numbers and group- 

 ing, lies the aggregate impression of richness 

 and variety, or of poverty and monotony of 

 vegetable nature. 



In this brief consideration of the phenomena 

 of organized beings, I have ascended from the 

 simplest cell(*°'), and so, from the first breath 

 of life, to higher and higher forms. " The ag- 

 gregation of mucus-granules into a definitely 

 formed cell-germ, around which a membrane 

 in form of a vesicle being developed, it is con- 

 nected into a closed cell," is either effected by 

 a pre-existing cell, so that cell arises from 

 cell(*''^), or the evolution of cells is involved 

 in the obscurity of a chemical process, as in 

 the case of the torula cerevisiae, or yeast fun- 

 gus. The most mysterious subject of Incipien- 

 cy can only be lightly touched upon here. The 

 geography of organized beings — plants and ani- 

 mals — treats of the germs already developed, 

 of their habitats from migrations effected on 

 purpose or accidentally, of their respective re- 

 lations, and their aggregate distribution over 

 the surface of the earth. 



The general delineation of nature, which I 

 here endeavour to present, would remain in- 

 complete, were I not to yield to the disposition 

 I feel, with a few touches, to portray the hu- 



