318 J. LeConte on Binocular Vision. 
Of course, by this shifting of the two fields all objects are simi- 
larly doubled. 
middle visual line. : : 
8. In turning the eyes in any direction without altering their 
Y a cular space ; this dal 
untary and habitual, and would of itself double all objects id 
tonymously ; 2d, in ocular convergence, a rotation of each fie 
