SEX IN LIVING FORMS 75 



Simplest Form of Generation. — Deep down be- 

 neath the waters of the ocean, covering its bottom in 

 certain localities, is found a curious slime, which, under 

 the microscope, is seen to be composed of minute 

 rounded masses of gelatinous matter, or protoplasm, 

 mentioned in a previous chapter. By watching these 

 little bodies intently for a few minutes, the observer 

 will discover that each is a living creature, capable of 

 moving, growing, and assuming a variety of shapes. 

 Continued observation will reveal the fact that these 

 little creatures multiply; and a more careful scrutiny 

 will enable him to see Jioiv they increase. Each divides 

 into two equal parts so nearly alike that they cannot 

 be distinguished when apart. In this case, the process 

 of generation is simply the production of two similar 

 individuals from one. 



Low Forms of Life. —A small quantity of slime 

 taken from the surface of a stone near the bottom of 

 an old well, or on the sea-side, when placed under the 

 microscope, will sometimes be found to contain large 

 numbers of small, round, living bodies. Careful watch- 

 ing will show that they also multiply by division; but 

 before the division occurs, two cells unite to form one 

 by a process called conjugation. Then, by the division 

 of this cell, instead of only two cells, a large number of 

 small cells are formed, each of which may be consid- 

 ered as a bud formed upon the body of the parent cell, 

 and then separated from it, to become by growth an in- 

 dividual like its parent, and, like it, to produce its kind. 

 In this case, we have new individuals formed by the 

 union of two individuals which are to all appearance 

 entirely similar m every particular. 



Sex.— Rising higher in the scale of being, we find 

 that, with rare exceptions, reproduction is the result of 



