51 



1 c.c. After having been kept herein for 24 hours they 

 were taken out, well washed on the outside, and, except 

 one mussel which was used immediately for analysis, the 

 others were transferred to a clean tub, were covered with 

 sterile sea water and clean well washed seaweed. After six 

 hours the water was poured off except as was sufficient to 

 keep the mussels in a wet condition. Under natural con- 

 ditions the mussels are covered with water at the flood tide 

 and uncovered with the ebb. The above procedure, viz., 

 clean tub, sterile sea water and weeds, was repeated every 

 24 hours, and each time, i.e., each 24 hours, the excess of the 

 water was only allowed to cover the mussels for six hours. 

 In this way the majority of the mussels could be kept alive 

 and in normal condition for seven days after they were taken 

 out of the infected water. All those that were examined after 

 opening looked perfectly normal in every respect, and contained 

 a considerable amount of liquor. As with the oysters and 

 cockles after opening, the fluid within the shell was drained 

 off as completely and as carefully as possible, then the whole 

 fish was taken out, finely minced and well mixed, and of the 

 fluid a definite amount was used for cultivation in a Drigalski 

 plate. The mussels were chosen just as they came to hand, 

 some being large, some medium sized. 



Mussel 1 (large), kept in infected sea water for 24 hours 

 total amount of fluid a little over 2 c.c. : added -^ of this to 

 10 c.c. sterile sea water ; of this dilution used T J^ c.c. for one 

 Drigalski plate. This plate yielded 300 colonies ; this would 

 mean a little over 6 millions B. typhosus per mussel, viz., 

 300 x 100 X 100 x 2 = 6,000,000. 



Mussel 2 (medium size), total amount of fluid 4 c.c., after 1 day's 



change contained 74,800 B. typhosus per mussel. 

 3 (large), total amount of fluid 2-4 c.c., after 2 days' 



change contained 628,660 B. typhosus per mussel. 

 4 (medium size), total amount of fluid 1 8 c.c., after 3 days' 



change contained 36,000 B. typhosus per mussel. 

 5 (medium size), total amount of fluid 2 5 c.c., after 5 days' 

 change contained 58,000 B. typhosus per mussel. 



E 2 



