470 
C. A. MAC MUNN. 
Cheirocephalus. 1 Mr. Sorby has been inclined to doubt the 
exact identity in position of the bands of haemoglobin in the 
blood of Planorbis with those of vertebrate haemoglobin, but 
Prof. Gamgee shows that the bands there occur in the same 
position as those of vertebrate haemoglobin — a statement which 
I can confirm. 2 
Haemocyanin. — The blood of many Mollusks and Arthro- 
pods is of a blue colour after exposure to the air, and this is 
in most cases due to the presence of another pigment — haemo- 
cyanin. This pigment has quite an extensive literature of its 
own. It is not within the scope of this paper to refer to all 
the work that has been done with regard to the latter colour- 
ing matter, so I will dismiss the matter in as few words as 
possible. In 1816 Ermann had observed the blue colour of the 
blood of Helix, which he thought was due to opalescence; 3 
E. Witting 4 observed the feebly bluish blood of Unio pic- 
torum, also that of Astacus, but he missed the blue colour 
in the latter case. Genth 5 observed the blue colour of the 
blood of Limulus cyclops in 1852. Rouget in 1859 made 
some observations on the blood of Octopus vulgaris (also on 
that of Sipunculus oxyurus 6 ). In 1847 Harless and von 
Bibra observed the blue colour which the blood of Helix 
pomatia acquired on exposure to air and lost on treatment 
with CO„ ; they also observed that ammonia removed the blue 
colour, which came back on neutralising with hydrochloric 
acid. 7 They stated that this blood contained copper, but no 
1 Lumbricus and Arenicola also contain haemoglobin in their blood. 
Also Eunice. 
3 ‘Physiological Chemistry,’ vol. i, 1880, pp. 130, 131. Dr. Mays has 
obtained haemin crystals from this blood. Cf. Krukeuberg, loc. cit. 
3 “ Wahrnehmungen iiber das Blut einiger Mollusken,” ‘Abhandl. d. K. 
Akad. d. Wissen. zu Berlin aus den Jahren 1816, 1817 ’ (Berlin, 1819), 
S. 199—218. 
4 “ Ueber das Blut einiger Crustaceen und Mollusken,” ‘ Journ. f. pract. 
Chemie,’ Bd. Ixxiii, 1858, S. 121 — 132. 
5 “ Ueber die Asclien bestandtheile des Blutes von Limulus Cyclops 
(Fabr.),” ‘Ann. d. Chem. u. Pliarm.,’ Bd. lxxxi, 1852, S. 68 — 73. 
6 ‘Journ. d. la Physiol.,’ t. ii, 1859, pp. 660 — 670. 
7 ‘Muller’s Archiv,’ 1847, pp. 148—157- 
