1904 - 5 .] Dr W. Peddie on some Views regarding Vision. 951 
the field of vision, the star disappeared. It was quite invisible 
through a dark patch ; through a brighter patch it was visible, 
though apparently less distinct. 
It seems therefore that direct vision, when unobstructed by 
patches of self-colour in the eye, is most effective for perception 
of small luminous objects. Such a conclusion removes the basis 
from some theories of the mechanism of vision. 
{Issued separately October 23 , 1905 .) 
