384 PROCESSES OP LIFE REVEALED BY THE MICROSCOPE. 



AYhat, then, are the manifestations of the life energy* and what are 

 the processes which are discernible 1 ? All of us, in whatever walk of life, 

 will recognize the saying of Gould : 



Now, when one looks about him the plainest, largest fact he sees is 

 that of the distinction between living and lifeless things. 



As life goes on and works with power where the unaided eye fails to 

 detect it, the microscope — marvelous product of the life energy in the 

 brain of man — shows some of these hidden processes. It has done for 

 the infinitely little on the earth what the telescope has done for the 

 infinitely great in the sky. 



Let us commence with the little and the simple. If a drop of water 

 from an aquarium, stream, or pool is put under the microscope many 

 things appear. It is a little world that one looks into, and like the 

 greater one that meets our eye on the streets, some things seem alive 

 aud some lifeless. As we look we shall probably find, as in the great 

 world, that the most showy is liable in the end to be the least interest- 

 ing. In the microscopic world there will probably appear one or more 

 small rounded masses which are almost colorless. If one of these is 

 watched, lo! it moves, not by walking or swimming, bi?t by streaming 

 itself in the direction. First a slender or blunt knob appears, then into 

 it all of the rest of the mass moves, and thus it has changed its posi- 

 tion. If the observation is continued, this living speck, which is called 

 an amoeba, will be seen to approach some object and retreat, indeed, it 

 comports itself as if sensitive, with likes and dislikes. If any object 

 suitable for food is met in its wanderings the living substance flows 

 around it, engulfs it and dissolves the nutrient portions and turns them 

 into its own living substance; the lifeless has been rendered alive. If 

 the eye follows the speck of living matter the marvels do not cease. 

 After it has grown to a certain size, as if by an invisible string, it con- 

 stricts itself in the middle and finally cuts itself in two. The original 

 amceba is no more, in its place there are two. Thus nearly at the bot- 

 tom of the scale of life are manifested all of the fundamental features — 

 the living substance moves itself, takes nourishment, digests it and 

 changes nonliving into living substance and increases in size; it seems 

 to feel and to avoid the disagreeable and choose the agreeable, and 

 finally it performs the miracle of reproducing its kind, of giving out its 

 life and substance to form other beings, its offspring. 



It is the belief of many biologists that the larger and complex forms, 

 even up to man himself, may be considered an aggregation of structural 

 elements originally more or less like the amoeba just described; but 

 instead of each member of the colony, each individual itself carrying- 

 on all the processes of life independently, as with the amoeba, there is 

 a division of labor. Some move, some digest, some feel, think, and 

 choose, some give rise to new beings, all change lifeless matter into 

 their own living substance. (See Plate XI.) 



The processes and phenomena by which a new individual is produced 

 are included under the comprehensive term embryology. 



