388 PICTURESQUE SKETCHES 



riads of animals and vegetables of the very simplest 

 organization, (Fomminifera, Medusa, Conferva, and 

 Fuel,) and these differ but little, whether we exa- 

 mine the waters of high northern latitudes, the seas 

 of the tropics, or those of the Antarctic zone ; and in 

 rocks that appear to have been formed in deep water 

 we find very generally the remains of similar animals, 

 as far as they are capable of being preserved ; their 

 range in a fossil state being as considerable in a ver- 

 tical direction as it is horizontally with regard to the 

 recent species.* 



These minute animals, standing as they do on 

 the extreme verge of animated existence, perform 

 also, in all probability, (a suggestion for which we 

 are indebted to Professor Owen,) the important office 

 of bringing back into circulation a vast quantity of 

 organized matter, just when on the point of being 

 dissipated into its chemical elements. The animal- 

 cules soon become the food of other creatures of 

 somewhat higher organization; and they supply in 

 this way, and very rapidly, sufficient nourishment for 

 the numerous and voracious tribes of Mollusca, crus- 

 taceans, and fishes that inhabit the water. 



The course of nature in this respect seems to have 

 been at all times the same. Certain Mollusca of 

 low organization, the so-called Brqchiopoda, not many 

 steps removed from the animals of the former group 

 (Zoophyta), appear to have been, next to them, 



* In the case of infusorial animalcules, the same species (the inha- 

 bitants of fresh water) have been found living in the southern extremity of 

 South America and in Europe ; while species at one time supposed to be 

 peculiar to America, have been found associated with African land species 

 in the dust that has fallen upon vessels far out at sea in the Atlantic. 



