64 



growth of those seasons, should be in the ascendant naturally, and hence the small ratios on the 

 upper section. 



Apparently the ratios should be about the same on the middle section, as its successive spat- 

 ting season was also in 1876-'77; but the moderately successful season was in 1878, while on the 

 upper section it was in 1879; and as brood oysters are constantly taken from the beds in constantly 

 increasing numbers it follows that the yield of each succeeding year will be less. As an addi- 

 tional cause, more of the beds iu the upper section are worked during the summer than in the 

 others. 



During the season of 1878 there was an extraordinary growth of young on Harris' bed, which 

 accounts for its large ratio, and the increase of the other ratios over those of the first section is 

 due to some extent to the attachment of the season of 1878. 



On the lower section the ratios are very large by reason of the successful attachment in 1878, 

 and the but moderate success of the seasons of 1876-'77. 



The variations iu the ratios can thus be accounted for by the success or failure of different 

 spatting seasons, and no doubt this success or failure has its influence, but that its effects are not 

 invariable can be seeu by reference to the ratios of Pocomoke Sound. 



With the exception of Parker's Bed, a small bed lying near Watt's Island and which has not 

 been dredged as extensively as the others in Pocomoke Sound, we find the ratio of young growth 

 to mature oysters exceedingly small. In no case do the former predominate. From this, accord- 

 ing to the deductions from the Tangier beds, it would be inferred that the seasons of 1876 or 1877 

 were unusually successful ones for the attachment of the spat, and that subsequently there has 

 been no successful season. 



By referring to the spatting table we find, however, that the spatting season of 1876 or 1877 

 was on the whole unsuccessful, and the seasons subsequent have either been successful or moder- 

 ately so, and this conclusion is supported by our observations during 1878. But as the success or 

 non-success as shown by the spatting table is comparative only, we can only assume that whether 

 successful or not the attachment was uot sufficient as one explanation of the small ratios found in 

 Pocomoke. 



Consequently the variation in the success of different spatting seasons is not sufficient to 

 explain unusual and abnormal changes in the ratios of the young growth to the mature oyster. 



It is evident that the removal of a large number of mature oysters from a bed would show 

 apparently an increased fecundity, by increasing the ratio of young growth to mature oysters, and 

 this apparent increase would be observable for at least two years, or until the young growth 

 became in turn mature, when, as the reproduction would naturally be diminished by the removal 

 of the brood oysters and consequently there would be a smaller number of young growth, and as 

 the young growth of the previous year would be in that time mature, the ratio would suddenly 

 turn in the opposite way, and be as abnormally small as it had been abnormally large. Once 

 having taken this turn, and the fishing still continuing, the ratios would constantly decrease. A 

 few fluctuations might occur now and then, but the general tendency would be a diminishing one. 



Nature arranges her own laws of supply and demand, and the ratios she establishes between 

 the different classes in any community are most likely to be the necessary ones, and such are the 

 only ones that can be accepted as standards. We have established tbat upon the uuworked beds 

 in the Bay the ratio of young growth to mature oysters is about 1.5, but as this is the result of 

 but one season's observations, and those over a somewhat limited area, it would be rash to accept 

 that standard exactly or to draw rigid inferences from comparison with it. Therefore, in order to 

 allow a sufficient margin for the variations of different seasons and localities, it will be better to 

 consider the normal ratio as between L and 2, and consequently any increase or decrease of that 

 ratio will be an indication of diminished fecundity, and, all things remaining the same, the eventual 

 destruction of the beds. 



Comparing the ratios of the beds in the Sounds with that established as a standard, we find 

 that — 



1st. All beds above the Grass Tangier fall below the minimum ratio. 



2d. That the groups including Tangier Grass and Muscle Hole are within the limit, as are the 

 beds in the Manokin and Big Annemessex Bivers and the Woman's Marsh Bed. 



