J. LeConte on Binocular Vision. 171 
the inclination of the horopteric line with that plane becomes 
ess and less, until at 45° downward it becomes perpendicular 
and therefore the Horopter again expands into a plane at right 
angles to the median line of sight. 4. That in raising the 
visual plane upward toward the eyebrows, the inclination of 
the Horopter to the visual plane increases. 
e have given Meissner’s investigations more in detail, 
because by entirely different methods we have confirmed al- 
most all of them. 
_Claparéde by similar experiments fails to confirm the conclu- 
sions of Meissner and therefore rejects them. He concludes, 
from his own experiments and partly from calculation, 
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Words, he believes that the horop- 
ter is a surface which contains the 
horopteric vertical BAB’ fig. 13) 
the horopteric circle OAO of 
Prévost, and that in addition the 
Surface j 
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oy the fact that, while the point 
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