246 UTILIZATION OF MINUTE LIFE. 



Again, many Infusoria and Rhizopoda play an 

 important part in the phosphorescence of the sea. 

 The luminosity of the waves is entirely due to 

 them. 



Ehrenberg has detected an immense number of 

 fossil Infusoria (Fig. 31). At first they were found 

 principally in certain siliceous deposits near Berlin, 

 but they were afterwards recognized in all parts of 

 the globe. Most of the species are so admirably 

 preserved, on account of their siliceous and im- 

 perishable envelope, that they can be, at the present 

 day, minutely investigated and classed. 



These shell-like teguments of beings, invisible 

 to the naked eye, are found in large masses, 

 covering many miles of the earth's surface. 



They constitute masses of a delicate white 

 powder, known as Mountain meal (Berg-mehl, Germ. ; 

 Farine de montagne, French) . 



In Swedish Lapland, under a bed of decayed 

 moss, forty miles from Degesfors, in Umea Lap- 

 mark, is found an immense stratum of this sub- 

 stance. Chemical analysis shows it to be composed 

 of 22 per cent, of organic matter, 72 per cent, of 

 silica, 6 of alumina, and 0*15 of oxide of iron.* 



In times of scarcity, this " mountain meal" is 

 mixed with flour, and manufactured into bread for 

 the poor. These fossil Infusoria do not constitute 

 * This analysis was executed by Dr. Trail. 



