l80 RELICS OF PRIMEVAL LIFE 



All the creatures referred to above, notwithstand- 

 ing the differences in their skeletons, resemble each 

 other very closely in their soft parts, and come under 

 the general name of Foraminifera, a name having 

 reference to the openings by which the animal matter 

 within communicates with the water without, for 

 nutrition and respiration. Such creatures may be 

 regarded as the simplest and most ready media for 

 the conversion of vegetable matter into animal tis- 

 sues, and their functions are almost entirely limited 

 to those of nutrition. Hence it is likely that they 

 will be able to appear in the most gigantic forms 

 under such conditions as afford them the greatest 

 amount of pabulum for the nourishment of their 

 soft parts and for their skeletons. There is reason 

 to believe, for example, that the occurrence, both in 

 the chalk and the deep-sea mud, of immense quan- 

 tities of the minute oval bodies known as Coccoliths 

 along with Foraminifera, is not accidental. The 

 Coccoliths appear to be grains of calcareous matter 

 formed in minute plants adapted to a deep-sea habi- 

 tat ; and these, along with the vegetable and animal 

 debris constantly being derived from the death of 

 the living things at the surface, and falling to the 

 bottom, afford the material both of sarcode and 



