250 



Dr. C. A. MacMunn. Researches on 



[Nov. 26, 



the blood-vessels with salt solution, I found the bands became much 

 better marked. 



Thus : — In fishes they have been observed in the tench, herring, 

 roach, eel, and others. 



In reptiles, in Tropidonotus natrix, Bascanium constrictor^ Scincus 

 officinalis, Trionyx, JEmys Europcea, Lacerta viridis, and Lacerta agilis. 



In Amphibians, in Rana temporaria, Hijla arborea, Bufo vulgaris, 

 Salamandra maculosa, Siredon pisciformis, and others. 



In birds, e.g., pigeon, owl, turkey, goose, duck, swift, &c. The gizzard 

 of birds is, however, mainly coloured by oxyhemoglobin. 



In Mammals, e.g., dog, cat, rat, rabbit, guinea-pig, hedgehog, sheep, ox, 

 pig, mouse, and man, as well as in others. 



In all cases oxidation and reduction could be brought about. When 

 the bands are invisible they can be brought into view by dipping the 

 portion of organ or tissue into Stokes's fluid,, or into a weak solution 

 of ammonium sulphide in water ; on exposure to the air they become 

 faint. 



Myohcematin. — All the species enumerated and others have been 

 examined for myohmmatin, and in all those which possess striped 

 muscle it has been found. 



Thus in molluscs, it is found in the heart and pharyngeal muscle of 

 Limax, Arion, Helix, and other pulmonates. 



In Arthropods, in the cardiac muscle of Homarus, Astacus, Cancer, 

 Carcinus, and Pagurus, and not in their voluntary muscles (so far) ; 

 also in the muscle of the cephalo-thorax of such spiders as Epeira 

 diadema, Tegenaria civilis (and others). 



In insects it is abundantly present, especially in the muscles from the 

 thorax. It is best marked in those which move the wings actively, 

 such as diurnal and nocturnal lepidopters. So far it has been found 

 in the following insects : — Musca vomitoria r domestica, and chlora, 

 Apis mellifica, Bomb us terrestris, Vespa vulgaris, Hydropldlus, Dyticus 

 marginalis, Geotrupes stercorarius, Lucanus cervus, Coccinella, Staphy- 

 linus olens, Gerambyx moschatus, Greophilus maxillosus, Carabus violaceus, 

 Periplaneta orientalis, Oryllus domesticus T Acrid a viridissima, Tipula 

 oleracea, Pieris rapae, and various other lepidopters and dipters. It- 

 has also been found in the mouth parts of larvse. 



Among vertebrates it has been found in the heart and voluntary 

 muscle of all the fishes, reptiles, amphibians, birds, and mammals 

 enumerated above. It is frequently accompanied by haemoglobin .in 

 these classes, and sometimes replaced by it. It may be apparently 

 absent, but its bands may be brought into view by the use of reducing 

 agents. 



The spectrum of myohasmatin is remarkable for the sharpness and 

 narrowness of its bands, in which point it and the other histohasmatins 

 differ from any other known animal pigment. Three bands are 



