THE BEGINNINGS OP LIFE. 125 



visible with the naked eye to excessively minute par- 

 ticles. When one of these is submitted to microsco- 

 pical analysis it exhibits imbedded in a transparent, 

 colourless, and structureless matrix granules, cocoliths, 

 and foreign particles V 



But those who wish to make themselves acquainted 

 with the Protamcebtf, need not seek for them only in 

 comparatively inaccessible regions. They are in reality 

 common in the fine surface mud of many of our fresh- 

 water ponds, and may easily be detected by the skilled 

 microscopist when once he has familiarized himself 

 with their appearance. We have lately detected, in 

 material taken from such situations, organisms similar 

 in kind though much more minute than the Protamceba 



1 One of the most interesting subjects attaching to these lower organ- 

 isms of the Protistic kingdom, is the enquiry as to how they are nourished 

 whether, like plants, they live upon inorganic elements abstracted from 

 their environment, or, like animals, upon organic substances already 

 elaborated. Dr. Wallich has strongly maintained the former view in 

 opposition to Dr. Carpenter's opinions that the Foraminifera are 

 nourished after the fashion of animals. In these and in similar low 

 oceanic organisms he has frequently expressed his belief that ' nutrition 

 is affected by a vital act which enables the organism to extract hydrogen, 

 oxygen, carbon, nitrogen, and lime from the surrounding medium, and 

 to convert these ingredients into sarcode and shell material.' (' Monthly 

 Microscopical Journal,' January i, 1869.) This elimination of inorganic 

 elements, and their conversion into protoplasm, Dr. Wallich believes to 

 be dependent upon ' a special vital force inherent in the protoplasmic 

 mass itself, and diffused, in all probability, throughout its substance.' In 

 view of this hypothesis, or of certain modifications thereof, concerning 

 Protistic life, it is most interesting for us to learn, from the analyses 

 of Dr. Frankland, that a large quantity of nitrogen, both free and 

 combined, exists in the water of the Atlantic Ocean. 



