12 Life and Immortality. 



which, like sugar, starch and cellulose, are made up of the 

 three elements, carbon, hydrogen and oxygen, but are, com- 

 paratively speaking, poorly supplied with quaternary 

 compounds, or those which contain an additional element of 

 nitrogen. Animals, on the contrary, are rich in quaternary 

 nitrogenized compounds, such as albumen or fibrin. Still, 

 in both kingdoms we find nitrogenized and non-nitrogen- 

 ized compounds, and it is only in the proportion which these 

 sustain to each other in the organism that animals differ in 

 any way from plants. 



Before the invention of the microscope, no independent 

 voluntary movements, if we except the opening and closure 

 of flowers, and their turning towards the sun, the drooping 

 of the leaves of sensitive plants under irritation, and some 

 other kindred phenomena, were known in plants. Now, how- 

 ever, we know of many plants which are endowed, either 

 when young or throughout life, with the power of effecting 

 voluntary movements apparently as spontaneous and inde- 

 Dendent as those performed by the lower animals, the move- 

 ments being brought about by means of little vibrating cilia, 

 or hairs, with which a part or the whole of the surface is 

 furnished. When it is added that many animals are perma- 

 nently rooted, in their fully-grown condition, to solid objects, 

 it will at once be apparent that no absolute distinction can 

 be made between animals and plants merely because of the 

 presence or absence of independent locomotive power. 



There is, however, a test, the most reliable of all that have 

 been discovered, by which an animal may be distinguished 

 from a plant, and that is the nature of the food and the prod- 

 ucts which are elaborated therefrom in the body. Plants 

 live upon such inorganic substances as water, carbonic acid 

 and ammonia, and they have the power of manufacturing 

 out of these true organic materials, and are therefore the 

 great producers of nature. All plants which contain green 

 coloring matter, technically called chlorophyll, break up 

 carbonic acid in the process of digestion into its two 



