124 OYSTERS, AND ALL ABOUT THEM. 



to enable us to understand why it is that the increase of a 

 given stock of oysters may be, and usually is, very slight, 

 notwithstanding the prodigious fertility of the individual 

 oyster. A very large proportion of the oysters in a bed, 

 under ordinary circumstances, breed during the season ; 

 and as each adult female oyster, on an average, gives rise 

 to a million eggs, one would expect a prodigious increase, 

 even if nine-tenths of the young were destroyed. But 

 from the small proportion of half-grown to full-grown 

 oysters (40-50 per cent.), it is clear that the real addition 

 to the oyster population, in most years, is very small. It 

 is probable, in fact, that unless the conditions are unusu- 

 ally favourable, not more than two or three out of every 

 million of the fry of the oyster ever reach maturity. 



" It is obvious that the conditions of existence of the 

 oyster are of an extremely complicated character, and that 

 the population of an oyster bed, under natural conditions, 

 must be subject to great fluctuations. A few good spat- 

 ting years, accompanied by a falling-off in the number of 

 starfishes and dogwhelks (q), may increase it marvellously, 

 while the contrary conditions may as strikingly reduce 



it." 



A great amount of the miscellaneous information 

 regarding oyster-growth and oyster-commerce, which was 

 circulated a few years since (and the remark applies almost 

 as much to the present time), is not of a reliable nature ; 

 but many of the circumstances attendant on artificial 

 culture are interesting, and have been proved to be correct, 

 although they seem contradictory : as, for instance, that 



(g) In the Bay of Arcachon, 14,000 whelk tingles were picked off 100 

 acres of oyster ground in the course of a month. 

 (r) " Oysters and the Oyster Question." 



