274 DR, C. A. MAC MUM ON MYOHAEMATIN AND THE HISTOHaE MATINS. 
histohaematins can be recognised in the tissues or organs when squeezed out to a degree 
of thinness which no longer allows the bands of haemoglobin to be seen, and in most 
cases the blood-vessels can be injected with salt solution sufficiently to eliminate the 
influence of the circulating haemoglobin. 
Although Birds and Mammals present the best marked histohsematin spectra, yet 
to preserve the continuity of this paper Fishes will be dealt with first. I will, how¬ 
ever, deal briefly with this class, as the spectra of their organs are not as well marked 
as in other classes. In the golden carp ( Cyprinus ), the ma.ckerel ( Scomber scombrus), 
the herring ( Clupea heringus), the roach ( Leuciscus rutilus ), and the tench ( Tinea 
vulgaris), the stomach-wall, liver, kidney, and intestinal wall, and perhaps other organs, 
present histohsematin spectra. In some the spectra are obscured by the presence of 
oxyhsemoglobin, which appears sometimes to replace them. 
The spectrum yielded by the liver and kidney is that shown in spectrum 1, 
Chart II. # In some parts of the kidney the band shown there is apparently replaced 
by two resembling in this point the spectrum of the kidney in other animals. 
In other fishes similar spectra w 7 ere observed, and in every species examined I found 
myohaematin. 
Amphibians. 
In Rana temporaria a well-marked histohsematin spectrum can be seen in the 
stomach-wall, spectrum 2, Chart IT. The testis appears to contain traces of the same 
bands. The liver shows a band covering D, and a darker between D and E. In the 
spleen, besides that of reduced haemoglobin a similar spectrum occurs, also in the kidney. 
In Bnfo vulgaris the same organs show similar spectra. 
In Hyla arborea there are traces of similar spectra, but they are much obscured by 
the presence of oxyhsemoglobin. The spectrum of the kidney is worthy of notice. 
In Salamandra maculosa the histohsematin spectra in the kidney, liver, stomach- 
wall, and spleen are much obscured by the presence of haemoglobin, but there is distinct 
evidence of their presence. 
The Mexican Axolotl ( Siredon pisdformis ) presents well-marked spectra belonging 
to this class. Thus the liver shows a faint band at D, and another faint one between 
D and E, besides a third nearer violet, spectrum 3, Chart II. In the cortex of the 
kidney a well-marked histohsematin spectrum (spectrum 4, Chart II.), wdfich recalls 
myohaematin to mind. In the stomacli-v 7 all another even more closely resembling 
that of myohaematin, and in the intestine a similar spectrum (spectrum 5, Chart II.). 
In the so-called red frog (species l) the appearances are similar, the kidney 
showing the same double band between D and E as in Axolotl, &c. In the liver and 
spleen a histohaematin spectrum like that of Rana occurs. The stomach-wall shows a 
similar spectrum to that of the kidney, especially after immersion in weak reducing 
agents, such as water, to which a few drops of sulphide of ammonium have been added. 
In all these Amphibians myohaematin is found. 
* Ei’om the tench. 
