IN THE ANIMAL KINGDOM. 



13 



per 100 grams. Coincident with the appearance of Dubois's first article, 

 Dhere (Compt. rend. soc. biolog., 1900, LII, 458) reported the results of his 

 investigations of the quantity of copper in the blood of certain invertebrates 

 and the respiratory capacity of hemocyanin. His analyses were made with 

 10 c.c. of fresh blood in each case, and he gives the figures shown in table 3. 



It will be noted that the copper content varied much, not only in 

 different species, but also in members of the same species. He also found 

 that the intensity of blue coloration is in relation to the quantity of copper. 

 The respiratory capacities in relation to the quantity of copper and hemo- 

 cyanin are shown in table 4. 



TABLE 4. Respiratory capacities in relation to the quantity of copper and 

 oxygen in the blood, according to Dhere. 



Couvreur (Compt. rend. soc. biolog., 1900, LII, 395), in his studies of 

 coagulative and other phenomena of the blood of the snail, states, in opposi- 

 tion to Heim (loc. cit.) and in support of Jolyet and Regnard (loc. cit.), 

 that hemocyanin should be looked upon as being a combination of copper 

 with protein. In a later article (ibid., 1902, LIV, 125) he made compara- 

 tive studies of the bloods of certain marine gasteropods (Murex brandaris, 

 Murex trunculus, and Tritonium nodiferum) with the blood of the snail. 

 The hemocyanin of these bloods, like that of the snail, was precipitated by 

 saturation with magnesium sulphate. He also notes that the hemocyanin 

 of marine gasteropods seems to be more stable than that of the snail. Couv- 

 reur and Rougier (ibid., 1902, LIV, 1476), in comparing hemocyanin and 

 hemoglobin, note that hemoglobin is not broken down by putrefactive 

 processes while hemocyanin is, and that the normally blue blood becomes 

 dark and forms an insoluble product of a dark tint which is a derivative 

 containing copper. Dhere (ibid., 1903, LV, 1161) kept the bloods of Octopus 

 vulgaris, Cancer pagiirus, Carcinus mcenas, and Maia squinado in sealed tubes 

 for three years. The fluids were discolored, and upon being shaken with air 

 only the blood of Octopus became blue, while that of the crustaceans became 

 a slate-gray. He also made determinations of the percentages of copper. 



In other articles Dhe"r6 (ibid., 1903, 1012, 1338) and Couvreur (ibid., 

 1247) discuss the effects of dialysis, heat, alcohol, etc., on hemocyanin. 

 Henze (Zeit. f. physiolog. Chemie, 1901, xxxni, 370) found in the hemo- 

 cyanin of Octopus vulgaris 0.38 per cent of copper. The blood contained 



