^70 DR. C. A. MAC MIJNN OR MY OHiE MATIN AND THE HISTOHM1MATINS. 
of Krukenberg, my enteroheematin) of Helix. I was inclined at first to agree with 
Krukenberg for the reasons given above.* 
Histohcematins of Mollusca. 
In this sub-kingdom one meets with appearances which prove the great importance 
of the histohsematins from a physiological point of view, and prove them connexion 
with, and replacement by, pigments which are known to be connected with haemo¬ 
globin and its derivatives. Sorby’s remarks on the presence of certain bands in the 
foot of Helix have been given above. 
Littorina littorea. —Haemoglobin occurs in the pharyngeal muscled and I have 
changed it into haematin, both acid and alkaline, it here occupies the place of myohce- 
matin as a comparison with other species shows. 
In the yellower parts of the foot two faint bands like those of haemochromogen can be 
detected. In other fleshy parts of the body we get a spectrum which resembles 
myohaematin, if we suppose the second and third band of its spectrum to have 
coalesced (spectrum 3, Chart I.). 
Purpura lapillus. —Haemoglobin occurs in the pharyngeal muscle replacing the 
myohaematin of other species. 
In the foot, a histohaematin spectrum is visible, resembling that of Littorina 
(spectrum 4, Chart I.). In other parts of the animal no bands are with certainty 
visible, except in the liver (referred to in former papers), but here and there a faint 
histohaematin spectrum can be just seen. 
Trochus cinerarius. —The pharyngeal muscle contains haemoglobin. Contraiy to 
what I found in Littorina, it is absent from the radula. Faint traces of a histo¬ 
haematin are present, but none distinct enough to map. 
Patella vulgata. —Haemoglobin occurs in the pharyngeal muscle, and in the radula 
in traces. The foot shows a distinct histohaematin spectrum, and in other parts faint 
traces of its bands are just visible. 
In most specimens these bands resembled closely those of haemochromogen, and, 
since the latter is present in its “ bile,” as I have shown, there can hardly be a doubt 
that this pigment is taken up from the intestine and deposited in the tissues us a 
histohaematin. 
In Limnceus stagnalis and Paludina vivipara, besides the haemoglobin in the 
pharyngeal muscles, there is evidence elsewhere of the presence of a histohaematin, 
but the examination of these species is yet incomplete. 
In Mytilus edulis, in the mantle, a distinct histohaematin spectrum is apparent, and 
on comparing this with the spectrum of myohaematin and with other histohaematins a 
very striking likeness is apparent.| In the ovairies a somewhat similar spectrum is 
* Howell has, however, recently found haemoglobin in a HolotJiurian, which tends to support 
Fcettingbr’s statement. June 16, 1886.— Johns Hopkins University Circular, v., 1885. 
f And in the radula. In the liver of some I have detected bands like those of hmmochromogen. 
t After Stokes’s fluid the hands read 1st X 613-596 - 5; 2nd, X 569-563; 3rd, X 556-550. 
