122 Proceedings of Boy at Society of Edinhurgh. [sess. 
worms whose blood contains hsemoglobin and chlorocmorin, no 
proteid remains in solution ; but in the case of those whose blood 
contains hsemerythrin there is an additional proteid present, which 
coagulates at 7 0° C. 
In Siyunculus the blood-corpuscles contain a coloured fluid 
between the external wall and the central nucleus. It may be 
stated that this is probably the first appearance of a true coloured 
corpuscle, but it differs essentially from the coloured corpuscle of 
the Mammalia, for in the latter the colouring matter is distributed 
throughout the corpuscle. 
The hsemoglobin present in the blood of worms is identical in 
chemical composition with that present in the higher animals.* 
In Glycera, and a few other Annelids, the hsemoglobin is present 
in special corpuscles, but in the majority of these animals it is dis- 
solved in the plasma. 
The gases of the blood of the eleven Annelids (previously men- 
tioned) have been investigated by using the mercurial air-pump, ^.e., 
by the method which has been already described in the Proceedings 
of the Royal Society of Edinhurgli, vol. xviii. p. 288. This method 
gave the following results : — 
Oxygen. 
Carbonic ilnliydride. 
Nitrogen. 
SipunculiLS, 
12-31 
28-29 
1-82 
Hirudo, .... 
12-93 
29-62 
1-91 
Hcemophsis, 
12-99 
30-00 
1-94 
Lumhricus, 
13-02 
30-15 
1-96 
Sahella, . . 
12-50 
28-30 
1-89 
Serpula, .... 
12-46 
28-04 
1-83 
Arenicola, 
12-89 
30-12 
1-90 
Aphrodite, 
11-99 
28-20 
1-87 
Glyeera, . . 
12-87 
29-24 
1-89 
Terehella, .... 
12-90 
29-55 
1-76 
Nereis, .... 
12-82 
29-02 
1-84 
The above figures represent volumes of the gases per 100 volumes 
of blood (the volumes being reduced to 0° C. and 760 mm.), and 
they also represent the averages of three determinations in each 
case. 
The nitrogen is simply dissolved in the blood, but the oxygen 
* Dr Griffitlis in Proc. Roy. Soc. Edin., vol. xviii. p. 294. 
