28 THE WAY LIFE BEGINS 



The Father and Mother Reproductive Elements 

 in Plants and Animals are very Similar 



The ova or eggs of fish are produced by paired organs 

 called ovaries, attached to the back body-wall. In the breed- 

 ing season the eggs, which have heretofore been very small, 

 increase rapidly in size so that great numbers of them, many 

 thousands, indeed, fill the egg sacs of the female. Here they 

 are held until needed. The eggs in the ovules of plants, the 

 seed to be, are very similar, except that in the case of the 

 plant the organ that produces the eggs, the ovary, dies and 

 falls away when its work is done. In the fish it shrinks to 

 small size until the next breeding season. 



The sperm cells of the male fish, and the sperm cells found 

 in the pollen of flowers perform a similar service in reproduc- 

 tion. The two spermaries in the male fish are in the same 

 position as the ovaries of the female. The product of the 

 spermaries is a heavy, whitish, glistening fluid, called the 

 'milt'. Under the highest powers of the microscope this 

 'milt' is shown to be a mass of millions of moving cells. Each 

 cell is provided with a swimming tail or lash. These sperm 

 cells are so small that it would take six thousand or more of 

 them, placed side by side, to measure an inch. The 'milt' 

 is deposited in the water by the male fish in the immediate 

 vicinity of the eggs, which but a moment before, have passed 

 from the body of the female. By means of their swimming 

 tails, the sperms find their way to the egg, and one sperm cell 

 enters and merges with the nucleus of each egg. The sperm 

 cells in the pollen of plants accomplishes the same end, except 

 that the plant sperm cells have no swimming tails and must 

 depend upon the wind or insects to carry the pollen to the 

 pistil. 



The Interesting Story of the Salmon 



Fishes lay their eggs in many different places. Some are 

 scattered freely over the bottom of the stream, pond, or sea; 

 some are buried in the sand; some, like the cod, float upon 

 the surface of the ocean. A few fish, like the little stickle- 

 back, make special provision for their eggs and young by 



