EARLY DISCOVEETES BY THE MICROSCOPE. 25 



of nearly one hundred years, and come down to 

 1839. In that year, Professor Ehrenberg of 

 Berlin announced the astounding tidings that 

 he had discovered, beneath the foundations of 

 his own city of Berlin, a widely-extending bed 

 of earth teeming with living organisms. The 

 name Infusoria was first given to this newly 

 discovered race, because it was supposed that 

 they were chiefly to be found in infusions of 

 vegetable or animal matter. It is now under- 

 stood that this name, though still retained as a 

 general designation, is not, on the above ac- 

 count, thoroughly appropriate, as the infusoria 

 are found not merely when there is an infusion 

 of vegetable or animal substances, but where- 

 ever there is water. 



5. Ehrenberg still regards these creatures 

 generally as animacules, but many microscopists 

 deny this name to these organisms, and class 

 them with plants. In this, and in other ana- 

 logous cases, Professor Carpenter's remarks may 

 be carefully borne in mind. " The boundary 

 between the two kingdoms" (animal and vege- 

 table) " is not less keenly debated among natu- 

 ralists than that of many a disputed frontier 



