86 C. A. MAO MUNN. 
The colouring matter in the fresh state showed no bands 
except some shading at the blue end of green ; it also absorbed 
the violet end of the spectrum. These observations confirm 
those of Professor McKendrick,' as may be seen by consulting 
his paper. He also got the colouring matters from Cyanea 
and Aurelia by allowing fragments of these to macerate in 
sea-water for about thirty-six hours. In these cases ammonia 
precipitated the colouring matter from its solutions, and it 
dissolved in acids. Professor McKendrick states that after 
death “the body becomes slightly acid, the protoplasm dis- 
integrates, and the colouring matter diffuses out.” 
In Cyanea an infusion gave two distinct bands, one in the 
red and the other in the orange; they were also visible in the 
fresh pigment. 
The blue colouring matter of Rhizostoma Cuvieri gives 
three bands in the fresh state, one in the red, one at p, which 
is the darkest of the three, and another in the green, the last 
being extremely faint. On comparing this with McKendrick’s 
description it is evident that the same pigment occurs in 
Rhizostoma as in Cyanea. There must be something 
wrong in Krukenberg’s drawing of this spectrum? from Rhizo- 
stoma, as can be seen by inspecting it. Krukenberg calls this 
pigment “cyanein.”” He compares this “cyanein” with the 
blue colouring matter found in Velella limbosa by A. and 
G. de Negri,> which those observers found to change quickly 
after the death of the animal, and to be soluble in water in which 
on heating it became yellow. It was insoluble in ether, chloro- 
form, benzene, and bisulphide of carbon; it was coloured red by 
acids, and changed to an amethyst colour by alkalies. Kruken- 
berg afterwards (1884) thought that his “‘cyanein” does actually 
occur in Velella, Rhizostoma, Aurelia, and Cyanea. 
This “‘cyanein,” according to him, is easily soluble in fresh 
and in salt water. After adding acids in sufficient quantity it 
1 «Journ. Anat. and Physiol.,’ vol. xv, pp. 261—264. 
‘Vergl. physiol. Studien,’ zweite Reihe, dritte Abth., 1882, 8. 68. 
“ Sulla materia colorante della Velella limbosa,” ‘Gazz, Chim, Ital.,’ 
vii, fasc. iv, 1877, 
w eo 
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yol. 
