680 DAVID HILT TENNENT. 
McCrady found it in oysters at Charleston; it is found in 
abundance at Beaufort; it is plentiful in Pamlico Sound ; it 
occurs in Lonisiana; it was present in oysters which I pur- 
chased in Baltimore, and which were said to have come from 
the Rappahannock. 
The extent of infection varies. Of the Pamlico Sound 
oysters which I examined thirty were from Stumpy Point 
Bay; of these six or 20 per cent. were infected, none of them 
badly. From Juniper Bay Point I had twelve oysters, of 
which four or 33 per cent. were badly infected. 
In February, 1902, of seventy-two Rappahannock (?) oysters 
which I examined, four or about 5 per cent. were infected. 
As to the percentage of infected oysters at Cameron, I can 
give no data. They are said to be badly infected. 
At Beaufort, in 1901—1902, the percentage in several 
hundred oysters examined was from 25 per cent. to 25 per 
cent. 
Through the kindness of Dr. Grave I was enabled, in 1903, 
to make use of the beds which he had established in Newport 
River in his experiments on oyster culture. 
In June, 1903, one bushel of oysters from bed No. 6 gave 
32°5 per cent., while the other beds in the same region gave 
21 per cent. of badly infected oysters. 
In September, 1903, upon tonging upon bed No. 6 many 
oysters were found to have recently died. (Many shells, the 
valves of which were still attached, were tonged up.) Hx- 
amination of two bushels of the remaining oysters showed but 
3 per cent. infected. About one bushel was left in a heap in 
the water at one side of the wharf. On the day following it 
was noticed that the shells of some of the oysters were separ- 
ated, and that small crabs were present in large numbers and 
were feeding upon the dead oysters. ‘Twenty-eight of these 
crabs were taken. Examination of their stomachs showed 
that twenty-six contained cercaria oysters, the cercarie being 
dead in every instance. (Huet’s observations that the cer- 
caries seem to cause the death of the host and then escape 
into the surrounding water does not seem to be confirmed.) 
