THE OYSTER. 7 



to be a barren desert. If it be true that all animals 

 depend on plants for their food, the vegetation of the 

 ocean seems totally inadequate for the support of its 

 animal life. 



The microscope shows that its surface swarms with 

 minute plants, most of them of strange forms, totally 

 unlike any which are familiar; for they have nothing 

 in common with the well known trees and herbs and 

 grasses of the land except the power to change inor- 

 ganic matter into food which is fit for animals. 



Most of these plants are so small that they are abso- 

 lutely invisible to the unaided eye, and even when they 

 are gathered together in a mass, it looks like slimy 

 discolored water and presents no traces of structure. 

 They seem too insignificant to play any important 

 part in the economy of nature, but the great monsters 

 of the deep, beside which the elephant and the ox and 

 the elk are small, owe their existence to these micro- 

 scopic plants. 



Their vegetative power is wonderful past all expres- 

 sion. Among land plants, corn, which yields seed 

 about a hundredfold in a single season, is the emblem 

 of fertility, but it has been shown that a single marine 

 plant, very much smaller than a grain of mustard seed, 

 would fill the whole ocean solid in less than a week, 

 if all its descendants were to live. 



This stupendous fact is almost incredible, but it is 

 capable of rigorous demonstration, and it must be 

 clearly grasped before we can understand the life of 

 the ocean. As countless minute animals are con- 



