668 REPORT—1896. 
In the following series of experiments infected oysters were taken, the 
duplicates of which, as seen in the preceding table, contained comparatively 
large numbers of the B. typhosus, and were subjected to a running stream 
of pure clean sea-water. The result is definite and uniform ; there is a 
great diminution or total disappearance of the B. typhosus in from one to 
seven days. 
No. of 
Oyster | Inoculated | Washed | Examined a Kind of Organisms present 
Agar 
i Aug. 25 | Aug.26 | Aug.30 | 80 2 colonies B. typhosus 
ory 3 | Aug. 28 3 gee B. typhosus present 
3 (| Aug. 26 | + ” | 44 3 fe 
a: ” | Aug. 29 ” 40 ” ” 
5 Aug. 2 ” ” | 5 ” ” 
6 = = Aug. 31 700 abundant B. typhosus 
7 Aug. 28 | Aug. 30 Ege | meta B. typhosus present 
8 Aug. 26 | Aug. 28 Sept. 3 | 4 1 B. typhosus 
9 Aug. 27 Aug. 29 oi 10 no B. typhosus found 
10. 4 i * # 8 3 colonies of B. typhosus 
11 | Aug.28 | Aug.30 | Sept.4 | 4 1 colony of B. typhosus 
12 a Sept. 3 bs 200 mInajority B. typhosus 
13 Aug. 31 | 2 | - 4 
14 | Aug. 28 | Sept. 3 Sept.6 | 65 no B.typhosus, but Proteus 
15 =| Aug. 3l ES Be 5 ? B. typhosus 
16%) = Sept. 5 as | 70 one half colonies B. typhosus 
1 7 | Sept.3 | Sept. 10 1 no B, typhosus 
13} i; | Sept.5 | Sept. 11 2 ? B. typhosus 
V.—The Green Coloration and ‘ Green Disease’ in Oysters. 
We have been investigating the well-known green coloration of 
certain healthy oysters grown at Marennes and other places on the west 
and north coasts of France, and in the river Roach in Essex. It has 
long been known that copper has nothing to do with this green colour, 
but an attempt has lately been made to show that it is due to the presence 
of iron in the mud which is taken up by cells in the gills, &e. At our 
request Dr. Kohn has made a chemical analysis of oysters from a number 
of localities for us, and his results (given in detail as a separate paper) 
show conclusively that, while there are minute quantities of both iron and 
copper in all oysters, the amount present bears no proportion to the degree 
of green coloration. There is not more iron in the gills and labial palps 
than in the rest of the body, and there is, on the whole, more iron in 
ordinary white or yellow American and Dutch oysters than in the green 
‘huitres de Marennes.’ 
We have made experiments in the feeding of oysters with various 
strengths of a number of saline solutions of iron and of copper salts, with 
the result that, although in some of the experiments the oysters lived 
healthily for weeks, and the shells and other exposed parts became strongly 
coloured—green, blue, brown, and yellow, according to the salt deposited— 
in no case did the soft tissues take in any staining until after death. 
There was no evidence that any iron had been taken up by the animal. 
The cause and meaning of the green coloration of the French cultivated 
