DR. C. A. MAC MUNN ON MYOHiE MATIN AND THE HISTOHiEMATINS. 293 
pigment which I formerly described under the name of “ urohse matin,”* which is a 
pigment closely related to heematoporphyrin, and which may also appear in the 
urine when the adrenals are healthy if there be an excessive destruction of blood- 
corpuscles, as in acute rheumatism; in such cases there being more effete colouring 
matters present than the organs concerned in their further downward metamorphosis 
are capable of dealing with. I need not describe the characters of urohsematin more 
fully here, as I have done so elsewhere,t but merely call attention to the significance 
of its presence. 
Recent researches! on the development of the adrenals go to negative the idea that 
they are nervous ganglia, and I believe they may be looked upon as organs which 
are more or less supplementary to the liver, which have been developed at a later 
stage ( i.e ., a later stage in the ancestral development), when the animal body had 
become more complex, and a greater abundance of respiratory pigments had become 
necessary for internal and ordinary respiration; which entailed the setting apart of 
certain organs to carry on the increased “ division of labour in this case the function 
of these supplementary organs being the removal from the circulation of useless and 
worn-out pigments, and their accompanying proteids. 
Whether this view be correct or not, it fits in well with the teachings of physiology 
and pathology. For Tizzoni has shown that the removal of the adrenals is followed 
by pigmentation of the skin and mucous membranes, and in the majority of cases of 
Addison’s disease in which well-marked bronzing of the skin took place they have 
been found diseased. The occurrence of Addison’s disease without apparent disease 
of the adrenals can be easily explained on the hypothesis that they are supplementary 
organs, as other organs may do duty for them, but it remains to be proved whether, 
when they are apparently healthy in cases of bronzing of the skin, other conditions 
may not be present which hinder the discharge of their functions, such as obliteration 
of their arterial or nervous supply. 
No sufficient explanation has yet been offered as to the causation of Addison’s 
disease, and if the facts described in this paper should help to solve this problem it 
may induce others to follow up these observations, which at first sight seemed to have 
but the remotest bearing on human pathology. I have tried to obtain pigments from 
the adrenals by the use of various solvents, but as yet without result. 
Are there any grounds for supposing that the product of their metabolic activity 
may be derived from the histohsematins ? I believe this question may be answered 
in the affirmative for this reason, that in the integument of Uraster rubens, as already 
mentioned, lisematoporphyrin occurs as such, and here it is highly probable that it is a 
* Proc. Roy. Soc., vol. 31, p. 26, and vol. 35, p. 394 ; also ‘ Journal of Physiology,’ vol. vi., pp. 22 et seq. 
f Loc. cit. 
+ Compare W. P. R. Weldon “ On the Supra-renal Bodies of Vertebrates,” Quart. Journ. Micros. Soc., 
vol. xxv., pp. 137 et seq.; also Balfour’s “ Treatise on Comparative Embryology;” and Allen Thomson 
in the 9th Edition of “ Quain’s Anatomy.” 
