OYSTER CULTURE IN AMERICA. 807 



ally the western, than elsewhere, but its presence appeared 

 to have no effect upon the young or drills. East of the 

 bed the oysters were of the same general character as those 

 on it ; the same proportion of young growth was also 

 noticed ; but there was almost an entire absence of young 

 and drills. To the westward, as a rule, the oysters were 

 somewhat larger than^those on the bed, but as many young 

 growth were present as elsewhere. The number of young 

 and drills was, however, much diminished, as was also the 

 amount of red sponge. The number of oysters to the 

 square yard, the mean of thirty-six observations, was 0.70. 

 The number to the square yard, on the area occupied by 

 scattered oysters, the mean of seventeen observations, 

 was 0.07. 



DENSITIES. 



Specimens of the bottom water taken on each bed, at 

 all stages of the tide, have been tested with the hydrometer, 

 and its readings reduced to a standard temperature of 60 

 Fahr. These results show a maximum density of the 

 waters of Tangier Sound of 1.0164, which was found in the 

 lower part, about the California Rock, at half flood-tide. 

 The minimum density of i.oui was found in the upper 

 part of Fishing Bay, with the tide three-quarters ebb. 

 From the comparison of densities tabulated, it appears 

 that the state of the tide has but little influence upon the 

 density, though the depth of the water has, and the preva- 

 lence of strong winds may increase or diminish it. 



. . . . There were no heavy rains during my stay 

 in the Sounds, and the densities given (in the table) there- 

 fore show only the condition of the water in that respect 

 during dry weather. I was informed that there was a 

 noticeable change in its character about the mouths of the 



