I 



Frof. Ehrenberg's Researches on the Infusoria, 97 



Polygastrica—A. Rotatoria — 3. 



Closteriura lunula. (Anguillula fluviatilis.) 



Kolpoda cucullus. Diglena catellina. 



Monas termo. Kotifer vulgaris. 

 Navicula fusifonnis. 



Only one species has been found in all the points to which Dr 

 Ehrenberg's observations have extended, viz. at Sinai, Dongola, 

 Berlin, Petersburg, Bogoslofsk, and the Altai Mountains, the 

 Kolpoda cucullus. 



2. In Subterranean Waters, — As it was one of the principal 

 objects of Humboldt's journey through the Russian dominions 

 to examine all the more important mines in the empire, an op- 

 portunity was given to Dr Ehrenberg of determining the pre- 

 sence or absence of infusory animals in situations excluded from 

 the light of day, one of the principal agents in the production 

 of these animals upon the hypothesis of the generatio primitiva. 

 For this purpose he took the precaution of enclosing the stag- 

 nant water, mould, and other substances brought to the surface 

 for examination, in well dried glass flasks, so as to preclude the 

 possibility of their being carried thither from the surface ; and 

 in one instance, the depth was such that it was not even proba- 

 ble that they had penetrated so far along with the surface water, 

 but had been generated in the place where they were found. 



His endeavours were long unsuccessful. They were at last 

 found in tolerable numbers in two situations : 



1. At the depth of 56 archines (fathoms), in the silver mines 

 of Smeinogorsk, in the Altai Mountains, the following species : 



Anguillula fluviatilis, . . . , j*,'" 



Kolpoda cucullus, . . . . ji^ 



Loxodes cucullulus, .... ,'5 



■ ■ cucullio, . . . . ,»5 



It will be seen from the Russian table, that none of these spe- 

 cies were found at Smeinogorsk in the waters at the surface. 



2. At the depth of 6 archines, in the copper-mine of Soimon- 

 ofskoi, in the Southern Urals, in addition to the preceding 

 species, 



Monas atomus, . . . . j^^'" 



enchelys, • • • • liw 



—termo, . . . -1555 



OCTOBER — DECEMBER 1831. C 



