Page:Popular Science Monthly Volume 20.djvu/163

Rh probably show a diminished mortality, as the animal will be better able to protect itself as it increases in size, but the destruction among the unprotected, delicate embryos must be immense, and, as it is as great as fifty per cent, after attachment, it must be much more serious prior to that event.

From observations made during the summer of 1879, I find that, on a natural, unworked bed, the ratio of young oysters, or those over one and under two years of age, to those mature and over that age, is as one to two, or in a community of fifteen hundred there would be one thousand mature and five hundred young oysters.

There is no reason to suppose that, circumstances being favorable, this entire number does not spawn, for, of all those I have examined, I have never in the spawning-season found an animal that did not contain the generative matter, or that had not recently expelled it. Numbers send forth the products of generation at unfavorable times and in either an unripe or overripe condition, and some fail to void the fluids at all, but only unfortunate combinations of natural causes have those effects; and it is probable, if not absolutely certain, that in most spawning-seasons all the animals spawn. Dr. Brooks estimates the number of eggs voided by the American oyster at from nine to sixty millions; for convenience, we may take ten millions as the average number, which is probably less than what is actually the case. The thousand mature oysters in the community would, then, spawn ten billion eggs, and, as the young European oyster has been found to spawn about one third as many eggs as the mature animal, we will consider the same to be true for the American variety. The five hundred young would, then, spawn 1,600,000,000 eggs, or the total number in the community would spawn 11,600,000,000 eggs, from which would result five hundred oysters, or about twenty million eggs or oysters would perish where one was preserved!

It is evident, then, that the vast number of eggs spawned by the oyster is no assurance that even a small proportion of them will reach maturity, or that any external or abnormal agency, natural or unnatural, may not be sufficient to destroy the beds by removing either young or old oysters, or in other ways preventing them from reproducing their kind.

My personal observations convince me that the beds of Pocomoke Sound at least are in a condition very similar to the French beds before they were subjected to the action of protective laws; and, as the French beds have, by a wise and efficient protection, been made to yield again a profitable return, it will be instructive to see how that protection is afforded. Artificial cultivation in any way is not considered, as not being pertinent, and because, in however bad a condition our own fisheries may be, the time has not yet arrived when we will be reduced to those laborious and expensive methods of obtaining a supply of oysters.