UNIVERSALITY OF ANIMAL LIFE 353 



R diameter which does not exceed -^g-Vo f a ^ ne ' an< ^ J 6 * 

 these siliceous-shelled organisms form in humid districts 

 subterranean strata of many fathoms in depth. 



The strong and beneficial influence exercised on the feel- 

 ings of mankind by the consideration of the diffusion of life 

 throughout the realms of nature, is common to every zone, but 

 the impression thus produced is most powerful in the equa- 

 torial regions, 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 snow. The 

 local distribution 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 exten- 

 sive excavations, and sprung deep shafts, but I have also 

 found snow-white stalactitic columns encircled by the deli- 

 cate web of an Usnea, in caves where meteoric water 

 could alone penetrate through fissures. PodurellaB penetrate 

 into the icy crevices of the glaciers on Mount Rosa, the 

 Grindelwald, and the Upper Aar; the Chionaea araneoides 

 described by Dalman, and the microscopic Discerea nivalis 

 (formerly known as Protococcus), 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.* Whilst on the loftiest sum- 

 mits of the Alps, only Lecideee, Parmelias, and Umbilicariae, 

 cast their coloured but scanty covering over the rocks, ex- 

 posed by the melted snow, beautiful phanerogamic plants, as 

 the Culcitium rufescens, Sida pinchinchensis, and Saxifraga 

 boussingaulti, are still found to flourish in the tropical region 

 of the chain of the Andes, at an elevation of more than 

 15,000 feet. Thermal springs contain small insects (Hydro- 

 porus thermalis), gallionellae, oscillatoria, and confervas, whilst 

 their waters bathe the root-fibres of phanerogamic plants, 



great work, Die Infusionsthierchen als vollkommne Organismen, 1838, 

 8. 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 

 Bmaller infusoria live as parasites on the larger, and are 

 inhabited by others- s. 194, 211, and 512. 



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



2 A 



