1 68 PHYSIOLOGY OF THE INVERTEBRATA. 



observed "that ammonia removed the blue colour, which 

 came back on neutralising with hydrochloi'ic acid. They 

 stated that this blood contains copper, but no iron ; but 

 Gorup-Besauez * found iron also in its ash." 



In 1858, Dr. Witting recorded in his paper, " Ueber das 

 Blut einiger Orustaceen und Mollusken,""t that the blood of 

 Unio 'pidorum had a slight blue tinge. Similar observations 

 were made by Rougetj in 1859 on the blood of Ockypus 

 vulgaris. 



In I 867, the late Dr. Paul Bert§ described the blood of 

 Srjna as " feebly bluish, especially in the veins of the gills, 

 and that it acquired a bright blue colour on exposure to 

 air. This colour belongs to the plasma, and is not lost by 

 boiling." 



Rabuteau and Papillon|l in 1873 examined the blood of 

 Octopus, which became blue on exposure to air. They also 

 examined spectroscopically the blood of this animal, and 

 arrived at the conclusion that it gives no bands. But the 

 most remarkable paper on the blood of Octopus vulgaris is 

 that of Dr. Fredericq,1I published in 1878. He proved that 

 the blood contained hsemocyanin, and that the substance 

 was a proteid combined with copper. There is no doubt that 

 the blueing of the Molluscan as well as Crustacean blood is 

 due to the oxidation of ha^mocyaniu, and that hfemocyanin is 

 the carrier of oxygen within the system. 



The blood of Hdic and Arioii was also shown by Fredericfj 

 to contain liremocyanin, and to give no absorption 

 bands. 



Among the Moll asm, the late Dr. Krukenberg** examined 

 the blood of IJlcdonc iiwschata, Sepia officinalis, Zimna'us 



* Lehrbiich der l^JiijsivlogiscJieii C/iniiip, p. 369. 



f Journal fiiv Fractisclie CJieiiiic, Bd. 73, s. 121-132. 



J Journal de lu Plii/si'oloyie, t. 2, p. 660. 



§ Comptes-Rcndus, t. 65, p. 300. 



II Coniptes-liendas, t. 77, p. 137. 



^ Bulletins de VAauUniie liojjuh de, BeUjlque, 2 serie, t. 46. 



** Verglelchtnd-plujshlo'jisdie Studien, ist Reihe, 3 Abth., 1880, s. 72. 



