344 cosMoa. 



vegetable kingdom, on the contrary, acts upon our imagination 

 by its continued presence and by the magnitude of its forms ; 

 for the size of a tree indicates its age, and here alone ag^e is 

 associated with the expression of a constantly renewed vigor.* 

 In the animal kingdom (and this knowledge is also the result 

 of Ehrenberg's discoveries), the forms which we term micro- 

 scopic occupy the largest space, in consequence of their rapid 

 propagation.! The minutest of the Infusoria, the Monadidse, 

 have a diameter which does not exceed 3 oVo^^ ^f a line, and 

 yet these silicious-shelled organisms form in humid districts 

 subterranean strata of many fathoms in depth. 



The strong and beneficial influence exercised on the feelings 

 of mankind by the consideration of the diffusion of life through- 

 out the realms of nature is common to every zone, but the im- 

 pression thus produced is most powerful in the equatorial re- 

 gions, in the land of palms, bamboos, and arborescent ferns, 

 where the ground rises from the shore of seas rich in mollusca 

 and corals to the limits of perpetual snov/. The local distri- 

 bution of plants embraces almost all heights and all depths. 

 Organic forms not only descend into the interior of the earth, 

 where the industry of the miner has laid open extensive ex- 

 cavations and sprung deep shafts, but I have also found snow- 

 white stalactitic columns encircled by the delicate web of an 

 Usnea, in caves where meteoric water could alone penetrate 

 through fissures. Podurellae penetrate into the icy crevices of^ 

 the glaciers on Mount Rosa, the Grindelwald, and the Upper 

 Aar ; the Chionsea araneoides described by Dalman, and the 

 microscopic Discerea nivalis (formerly known as Protococ- 

 cus), exist in the polar snow as well as in that of our high 

 mountains. The redness assumed by the snow after lying on 

 the ground for some time was known to Aristotle, and was 

 probably observed by him on the mountains of Macedonia.! 



* Humboldt, Ansichten der Nairn- (2te Ausgabe, 1826), bd. ii., s. 21. 



t On multiplication by spontaneous division of the mother-corpuscle 

 and iutercalation of new substance, see Ehrenberg, Von den jetzt leben- 

 den Thierarten der Kreidebildung, in the Abkandl. der Berliner Akad. 

 der Wiss., 1839, s. 94. The most powerful productive faculty in na- 

 ture is that manifested in the Vorticellse. Estimations of the greatest 

 possible development of masses will be found in Ehrenberg's great 

 work. Die Infus^ionsthierchen als vollkommne Organismen, 1838, s. xiii., 

 xix., and 244. " The Milky Way of these organisms comprises the 

 genera Monas, Vibrio, Bacterium, and Bodo." The universality of life 

 is so profusely distributed throughout the whole of nature, that the small- 

 er Infusoria live as parasites on the larger, and are themselves iii&abit- 

 ed by others, s. 194, 211, and 512. 



t Aristot.. Hist. Animal., v. xix., p. 552, Bekk. 



