DR. C. A. MAC MUNN ON MYOH2EMATIN AND THE HISTOH2E MATINS. 273 
same situation in the crayfish. The green-gland gives the same spectrum as that of 
the latter species also (spectrum 16, Chart I.). In the vas deferens and the branchiae 
no bands could be detected. 
In Cancer pagurus and Carcinus mcenas similar spectra* were observed. In Pagurus 
bernhardus, whose heart muscle contains myohsematin, there are faint traces of 
histohsematins, but not distinct enough to map their spectra. 
Among Insecta, as already stated, the presence of histohsematins is difficult to 
determine. In the crop and other parts of the enteron faint bands coincident with 
those of histohsematin may be seen in some species ; one might expect to meet with 
myohsematin in this situation owing to the muscle of the intestine being striped 
in insects, but hitherto I have not found it. In the mouth parts of some larvse 
myohsematin occurs (e.g. Ennomos), and, as will be shown again, all adult insects 
possess myohsematin in their voluntary muscles. 
In Staphylinus olens we meet with a most remarkable spectrum, yielded by the 
testes, which shows that the hsemoglobin-forming tendency is not altogether sup¬ 
pressed in insects. I have not met with this appearance in other species. 
In the specimens of Staphylinus examined the testes were a fine carmine colour ; 
squeezed out in the compressorium, and examined in the usual manner, they gave two 
bands possessing a remarkable resemblance to those of reduced haematin (spectrum 17, 
Chart I.). Before squeezing down the cover-glass of the compressorium the spectrum 
resembled oxyhsemoglobin, but in a suitable thickness the bands appeared as shown. 
It will be noticed the first band is placed over a shading which occupies nearly the 
position of the band of reduced haemoglobin. The position of these bands is approxi¬ 
mately : 1st, \ 569 to X 554'5, and 2nd, X 540 to X 524'5. I succeeded in converting 
this pigment into acid haematin by the action of acetic acid, by which the bright red 
colour was changed to a dull brown and the spectrum into that of acid haematin. As 
spermatozoa were easily seen in these organs with the microscope there can be no doubt 
as to their nature. 
Vermes. 
In Lu r mhricus\ and Hirudo all the organs which in other species show histohsematin 
spectra appear to contain a small amount of haemoglobin, which doubtless functions 
in a similar manner to the histohsematins. 
In Aphrodite, besides the haemoglobin contained in the ventral chain of ganglia, I 
have detected traces in the muscular fore-amt. 
Histohcematins in Vertebrata. 
In F ertebrata the search for histohaematins in the organs and tissues is attended 
with difficulty, owing to the presence of haemoglobin, but fortunately the bands of the 
* The liver of Carcinus moenas shows a hand before D and a dark one in green. 
t Lumbricus contains heematoporphjrin in the dorsal streak. For Serpula and Sabella see my paper 
“ On the Chromatology of the Blood of some Invertebrates,’' Quart. Journ. Micros. Science., vol. C., p. 469. 
MDCCCLXXXYI. 2 N 
