histohaematin

from The Collaborative International Dictionary of English v.0.48

Histohaematin \His`to*h[ae]m"a*tin\, n. [Gr. "isto`s tissue + E.
   h[ae]matin.] (Physiol.)
   One of a class of respiratory pigments, widely distributed in
   the animal kingdom, capable of ready oxidation and reduction.
   [1913 Webster]