SEA-FISHERIES LABORATORY. 203 



ascertain by other reagents which of the metals is present. 

 Very numerous tests were made with the blood obtained 

 from white Oysters, and micro-chemical reactions revealed 

 in some instances faint traces of copper. Haeniocyanin 

 has been described in the blood of Molluscs and apparently 

 in the blood of the Oyster. We have examined numerous 

 samples of blood taken from the white Oyster, but have 

 failed to get any blue colouration on exposure to air. In 

 the green Oysters a very faint blue colour has been noticed 

 in some cases on exposing the blood to air." 



I quote the following conclusion from the Eoyal Society 

 paper : — 



" Our results demonstrated the presence of copper in 

 comparatively large quantity in the green leucocytes, 

 chiefly in the American Oyster, but also in the " natives " 

 from Falmouth and other localities. We have shown 

 that the colour was in proportion to the amount of copper 

 present, and that the colourless leucocytes contained only 

 traces of that metal. The deposition of the copper in this 

 large quantity appears to us to represent a degenerative 

 condition. It was accompanied by a most striking- 

 increase of leucocytes, which tended to distend the vessels 

 and to collect in clumps, phenomena which are abnormal 

 in our experience in the Oyster. The presence of the 

 copper in the leucocytes in these cases might be compared 

 to that of the iron which is met with, in man, in some of 

 the leucocytes in cases of old haemorrhages, pernicious 

 anaemia, or in other cases where iron is set free. We 

 are not prepared to state whether copper in the food can 

 bring about this condition, but certainly we have abundant 

 evidence to show that it can occur where no copper mines 

 or other evident sources of copper are present. 



"We are inclined to suggest that the increase in copper 

 may be due to a disturbed metabolism, whereby the 



