THE NATURAL HISTORY OF THE OYSTER. 159 



young perhaps, remotely, a sort of fluid amnion. Our bivalve, how- 

 ever, does not spawn after the manner of mollusks generally. It is 

 in its own way viviparous. It does not emit eggs ; hut, at the proper 

 time, sends forth its young alive. The eggs are dislodged from the 

 ovaries, and committed to the nursing cai - e of the gill and mantel. 

 At first, each egg seems to he inclosed in a capsule. It is of a yel- 

 lowish color ; hut, as incubation or development progresses, the color 

 changes, first to a gray, then to a brown, afterward to a violet. This 

 is a sign that the time of eviction is at hand ; for Nature now issues 

 her writ to that effect. And wonderful little beings they are wheu the 

 writ arrives to vacate the homestead ; for whole troops of them can 

 go gracefully, and without jostling, through the maziest evolutions in 

 that tiniest sphere a drop of water. As cited by F. W. Fellowes, in 

 the American Naturalist, says M. Davaine : "Nothing is more curious 

 than to see, under the microscope, these little mollusks travel in a 

 drop of water, in vast numbers, mutually avoiding one another, cross- 

 ing each other's track in every direction, with a wonderful rapidity, 

 never touching, and never meeting." The parent-oyster has, indeed, 

 a prodigious family to turn out upon the world. But when this time 

 does come, though winter be near, her actions are summary, and the 

 wee bairns are every one ordered from home. They are spit forth, 

 or ejected from the shell. Filled with water, the valves are suddenly 

 snapped together. Every snap emits a small, whitish cloud. Though 

 a little of the milky fluid be in it, this whitish cloud is composed chiefly 

 of the tiny fry ; for, individually, they are almost invisible. Indeed, 

 who shall count the oyster's offspring ? Science, by her own methods, 



Fig. 2. The Spat. Otsters just born, highly magnified. 



* 



has made the computation ; and so she gives us the astounding assur- 

 ance that a single oyster, during one spawning-season, emits two mill- 

 ion embryos ! Each one, though scarcely larger than a pin-point, is 

 a lively little affair ; and such an odd little fellow, too ! In fact, it lias 

 scarcely any resemblance to its parent, either in external form or in- 

 ternal anatomy ; while, in habit, it differs as widely as does the flying 

 bird from the burrowing mole. Let us look a moment at Fig. 2. 

 These are young oysters just sent into the world. They are not so 

 large, by a good deal, as an ordinary pin's-head. How angular the 

 shell is ! And the internal organization is, as yet, very simple. And 



