F01UMINIFERA. 87 



passes at last entirely into the mass. The engulfed morsel is gradually 

 dissolved and digested. 



FORAMINIFERA. 



There is nothing small in Nature. The idea of littleness or great- 

 ness is a human conception a comparison which is suggested by the 

 dimensions of his own organs. Nature, on the other hand, compen- 

 sates smallness by numbers. The result produced by the bones of 

 some large animals is also accomplished by the accumulated spoils of 

 millions of animalcules. The history of the Foraminifera is a striking 

 example of this great truth. 



What, then, is a Foraminifer ? It is a very small zoophyte, a shell 

 nearly invisible to the naked eye ; for, in general, its dimensions 

 rarely exceed the two hundredth part of an inch ; in short, it is 

 strictly microscopic. Examine under a microscope the sand of the 

 ocean, and it will be found that one-half of it consists of the debris of 

 shells, of various but well-defined forms, each habitually pierced with 

 a number of holes. To this they are indebted for their name Fora- 

 minifera, horn, foramen, a hole. With these microscopic animalcules 

 Nature has worked wonders in geological times ; nor have the wonders 

 ceased in our days. 



Many beds of the terrestrial crust consist entirely of the remains of 

 Foraminifera. In the most remote ages in the history of our planet, 

 these zoophytes must have lived in innumerable swarms in the seas 

 of the period ; they buried themselves in the bottoms of the seas, and 

 their shells, heaped up during many ages, have finished by forming 

 hills of great thickness and extent. We may say, to give an example, 

 that during the Carboniferous period, a single species of these zoophytes 

 has formed, in Russia alone, enormous beds of calcareous rock. Many 

 beds of cretaceous formation are> in great part, composed of Forami- 

 nifera, and they exist in immense numbers in the white chalk which 

 covers and forms the vast mountains ranging from Champagne, in 

 France, nearly to the centre of England. 



But it is to the Tertiary formation that these zoophytes have contri- 

 buted the most enormous deposits. The greater part of the Egyptian 

 pyramids is only an aggregation of Nummulites inserted in the syenite. 

 A prodigious number of Foraminifera present themselves in the tertiary 



