84 SATURDAY LECTUKES. 



■wandered along its shores ; but I will lirst speak of an animal 

 that all are familiar with in anv event. 



THE OYSTER. 



The oyster in this country forms one of the most common 

 and most esteemed articles of diet, and if you wish to get 

 an accurate idea of the vast importance of the oj^ster indus- 

 try, I would refer you to Mr. Ernest Ingersoll's report recently 

 issued from the Census Office. How many persons, while 

 enjoying their oysters — stewed, fried, broiled, scalloped, or 

 from the shell — ever pause to consider anything but the 

 flavor? How many dream that the lifeless and almost 

 shapeless thing so grateful to their palate was at one time 

 a free and active creature, swimming about in the ocean 

 with considerable rapidity ! 



The oyster is older than man. Evolutionists recognize 

 that stability of life-conditions induces permanency of t3'pe, 

 and as the conditions under which the oyster lives must 

 have prevailed at a ver}^ early period of the Earth's history 

 we find that the fossil shells of its ancestors are scattered 

 throughout the world wherever ancient oceans had their 

 shores, while they particularly abound in the cretaceous 

 formation. Prof. White, curator of ^lollusca in this mu- 

 seum, has kindly loaned me some fossil forms which he 

 finds abounding in the cretaceous of the West. The^^ do not 

 differ materially from others found in the INIiocene, and you 

 will see that in all of the hundreds of thousands of years 

 that have passed since then, while, as Prof. Marsh, has so 

 well shown us, the present horse was evolving through the 

 various forms of Eohippus, Orohippus, Miohippus, etc., from 

 a typically five-toed ancestor, quite unlike its present self 

 and common to it and other ungulate mammals ; while other 

 terrestial animals were undergoing like mutations, the 03'ster 

 retained essentiallv the same form. 



However much they ma}' differ in size, appearance and 

 flavor, the present 03' sters of North America are all referable 

 to one species, scientificall}'' known as Ostrea virginiana Lister, 



