37 



TABLE III. 

 SEA WATER. 



Immediately after infection . 2,360,000 B. typhosus per 1 c.c. 

 Iday 126,000 



1 day after change . .*'. 250 



2 days . . per T V c.c. 



3 



*> 5) J) ... 55 55 



4 55 55 5) * , 5J JJ 



6 ,, ... 



PREVIOUSLY WET OYSTERS. 



Oyster 15 1 day after infection 84,000 B. typhosus per oyster. 



17 1 day after change 935 



192 days 105 



213 per T V c.c. 



236 



25 7 55 55 55 55 



PREVIOUSLY DRY OYSTERS. 



Oyster 16 1 day after infection 1,318,000 B. typhosus per oyster. 

 18 1 day after change 1900 



20 2 days 646 



j) 22 3 j, ,, ,, 713 3, ,, 



From this Table III it will be seen that the previously 

 wet oysters cleared themselves of the B. typhosus of the re- 

 infection in a remarkably short period, from 84,000 24 hours 

 after infection to 105 after two days' (i.e., twice) change of 

 the water, and no colonies of B. typhosus could be obtained 

 from ^ G c.c. that is, if any, they must have been less than 

 10 after three days' changes of the sea water ; in other words, 

 the oysters were even more successful in dealing with the B. 

 typhosus now than they were after the first infection (Ex- 

 periment II), for on looking back to Table II it will be 

 seen that from oysters originally infected with 40,000 B. 

 typhosus, even after six days in clean sea water, changed 



