158 PHOSPHORESCENCE IN 
trivirgatus, or Singe Dormeur (Sleepmg Monkey), 
described for the first time by Humboldt, under 
the name of Simia trivirgata, in his ‘ Recueil d’Ob- 
servations de Zoologie et d’Anatomie Comparée’ 
(vol. 1. p. 306). 
I have observed a brilliant scintillation m the 
eyes of man himself, but only once. The hght 
was of a metallic-pink colour, resembling, in ge- 
neral aspect, the green light emitted from dogs’ 
eyes. I only saw this in one individual, though 
I have examined many; but a friend of mine 
lately witnessed it in the eyes of a litle girl. 
Both subjects alluded to were remarkably de- 
licate. 
I do not think we can attribute this hght to 
phosphorescence, but rather, that it 1s owing to a 
phenomenon of reflection. J have never had an 
opportunity of ascertaining whether this luminosity 
of the eyes of human beings is visible in complete 
obscurity, as Rennger states was the case with the 
light emitted from the eyes of Simia trivirgata ; 
but it is certain that the scintillation in the eyes 
of a cat or a dog is not visible m complete dark- 
ness. 
In most cases it is not difficult to distinguish 
light which is reflected from hght which is directly 
transmitted to us from the illuminated body itself, 
by means of the phenomena to which reflected 
light gives birth in the polariscope,—-an ingenious 
