SEX IN LIVING FORMS 69 



are unnoticed by the casual observer. The microscope 

 reveals worlds of life that were unknown before the 

 discovery of this wonderful aid to human vision, — 

 whole tribes of living organisms, each of which, though 

 insignificant in size, possesses organs as perfect and 

 as useful to it, in its sphere, as do animals of greater 

 magnitude. 



Under a powerful magnifying glass, as previously 

 stated, a drop of water from a stagnant pool is found 

 to be peopled with curious animated forms ; slime from 

 a damp rock, or a speck of green scum from the surface 

 of a pond, presents a museum of living wonders. 

 Through this instrument the student of nature learns 

 that life in its lowest form is represented by a mere 

 atom of living matter, an insignificant speck of trem- 

 bling jelly, transparent and structureless, having no 

 organs of locomotion, yet able to move in any direc- 

 tion; no nerves or organs of sense, yet possessing a 

 high degree of sensibility; no mouth, teeth, nor organs 

 of digestion, yet capable of taking food, growing, 

 developing, producing other individuals like itself, 

 becoming aged, infirm, and dying,— such is the life 

 history of a living creature at the lower extreme of 

 the scale of animated being. 



As we rise higher in the scale, we find similar little 

 atoms of life associated together in a single individual, 

 each doing its proper share of the work necessary 

 to maintain the life of the individual as a whole, 

 yet retaining, at the same time, its own individual 

 life. 



As we ascend to still higher forms, we find this 

 association of minute living creatures resulting in the 

 production of forms of increasing complicity. As the 

 structure of the individual becomes more complex, and 



