THE ANIMAL KINGDOM. 



23 



nearly all that had been written on the subject of red water 

 from the days of Moses up to our own, gives a list of 

 twenty -two species of animals, and almost as many plants, 

 capable of communicating this blood colour. 



When Ehrenberg planted his tent by the shore of the 

 Red Sea, he had the rare good fortune to behold this sea 

 tinged with the blood-red colour to which, from the re- 

 motest antiquity, it has owed its name. At this very time 

 its waves deposited on the shore a gelatinous matter of a 



lli. The Ked Trictiodesmia {Trichodesniia rubra) seen under the Microscope. 



beautiful purple colour, which the great Prussian naturalist 

 recognized as being composed of only one microscopic alga, 

 the Red Trichodesmia, the sole cause of this celebrated 

 phenomenon. 



Water is not the sole domain of microscopic animalcules. 

 They are met with in the earth, in masses the capacity of 

 which exceeds all powers of calculation. Certain species, 

 the extreme minuteness of which does not equal the 1500th 

 part of a millimetre,^ form in some damp places, living beds 

 beneath the soil which are often several yards in thickness. 



In North America these animated strata are found as 

 much as twenty feet thick, and among the heaths of Lune- 

 burg there are some more than forty feet in thickness. The 

 city of Berlin is built upon one of these beds of animalcules, 



1 About the forty-five thousandth part of an inch; the millimetre being 0-39371 

 inch. 



