12 THE OYSTER. 



As the little plants are bathed on all sides by food, 

 they do not have to go through the slow process of 

 sucking it up through roots and stems, and they grow 

 and multiply at a rate which has no parallel in ordinary 

 familiar plants. They would quickly choke up the 

 whole bay if they were not held in check; but their 

 excessive increase is prevented by countless minute 

 animals which feast upon them and turn the plant 

 substance into animal matter, to become in their turn 

 food for larger animals. As a matter of fact, they are 

 not very abundant, but there is no difficulty in finding 

 them in any part of the bay, by straining the water 

 through a fine cloth. In this way we obtain a fine sedi- 

 ment, which is shown by the microscope to consist 

 almost entirely of them. 



The variety of these microscopic plants and animals 

 is very great, and a series of big volumes would be 

 needed to describe the microscopic flora and fauna of 

 the bay. Most of them occur in other waters as well, 

 but many are peculiar to the bay, which is an excep- 

 tionally favored spot for their growth. 



The exploration of this invisible world with a micro- 

 scope is an unfailing delight to the naturalist, but at 

 first sight it seems to have no particular bearing on 

 human life. The ability to turn inorganic mineral 

 matter into food for animals and for man does not 

 depend on size, and in this work the microscopic flora 

 of the bay is as efficient as corn or potatoes, but infi- 

 nitely more active and energetic. 

 ^ In the oyster we have an animal, most nutritious 



