44 Life and Love. 



has a blunt, pear-shaped form, and exhibits slight 

 amcKboid movements. In some crustaceans and 

 other arthropods, the cell is even more quiescent, 

 and may exhibit curious forms such as that figured 

 for the crayfish. The relatively dominant activity 

 may, however, wake up, and the sperm exhibit 

 active amceboid movements." 



The sperm-cells, be it remembered, are so mi- 

 nute as to be totally invisible to the naked eye. The 

 fertilizing fluid of the fish, for instance, gives no 

 hint of the presence of the sperm-cells until it is 

 viewed through the microscope. In studying na- 

 ture one soon comes to understand that size is 

 merely relative and essentially unimportant. A 

 creature invisible to the human e}e may be a 

 veritable mammoth compared to another creature 

 so tiny that the strongest powers of the microscope 

 have to be used to discover it. And so the sperm- 

 cells, although as invisible to the naked eye as 

 though they did not exist, have an organization 

 and a fleeting life of their own, — a life less fleeting, 

 and fraught with great results, if they meet with 

 conditions favorable to their development, and can, 

 by union with an egg-cell, help to create a comple.x 

 form. 



Upon examination and comparison of egg-cell 

 and sperm-cell we are particularly impressed by 

 the diff'erence in their power of independent motion. 



Activity is the law of the sperm-cell ; passivity, 

 of the egg-cell. 



