CHROMATOLOGY OF BLOOD OF SOME INVERTEBRATES. 481 
haemochromogen was just visible, and perhaps a second 
like its second band. 
In some Ser pulse whose blood was not red but brown, the 
bands before and after D reminded of chlorocruorin (sp. 13, Chart 
I). In these, too, the gills were not red, as in the other speci- 
mens, and failed to show a band. An aqueous solution of the 
blood of these specimens had a reddish tint by gaslight, and 
gave three bands, which read as follows : — First X 620’5 to 
X 595, second X 583 5 to X 570 5, third X 551 to X 532. On 
adding sulphide of ammonium the band before D read X 620'5 
to X 598, and a second band was visible after D, which could not 
be measured. On adding to this reduced fluid some caustic 
soda at first the only change produced was the disappearance 
of the faint band after D, but, after standing, sp. 14, Chart I, 
appeared, of which the bands read : first X 623 to X 607, 
second X 596'5 to X 579. This shows that the blood of these 
Ser pulse did not contain the same kind of chlorocruorin as 
Sabella, but a pigment very closely related to it, probably 
nearer to hsematin than it. I had not enough material 
for further study. 
In most cases the gills gave sp. 15, Chart I, while in 
others the band was slightly nearer violet. On extracting 
them with absolute alcohol an orange solution .was obtained, 
which strongly absorbed the violet end of the spectrum, and 
allowing only the red and beginning of the green to pass in a 
deep layer. In a shallow one a shading was seen from about 
X 509 to X 467 (?). This solution became blue, and then 
colourless with nitric acid, but was not much changed by 
hydrochloric acid. Caustic potash developed a more distinct 
shading, from X 509 to X 481. 
The red opercula gave a band covering D, sp. 16, Chart I; 
they vary much in colour, some being very red, while others 
are colourless, and in some gills the same band is seen. 
The band of sp. 15, Chart I, belonging to the gills, though 
resembling that of reduced haemoglobin, has no connection 
with it, as I found by extracting the gills with rectified spirit 
and caustic potash, and adding sulphide of ammonium, the 
