THE MOUNTAIN HARE 
Subsequently, in the course of a letter (“The Field,’’ March 25, 1905), 
he added: 
“ One very curious fact is that the pupil of the hare’s eye contracts 
during sleep. Several of my hares have been tame enough to sleep 
soundly in my arms, and I have repeatedly opened the sleeping lids 
and found the pupil no larger than this O, and I take the degree of 
contraction to indicate the profoundness of the sleep, as a thermometer 
does temperature. This contraction in darkness seems contrary to 
the ordinary law of Nature. What, then, will be said when I state that 
the hare’s iris conforms to that law under the influence of strong light ? 
For I have several times reflected the strongest light into my hare’s 
eyes by means of a hand mirror, and found that the pupil of the exposed 
eye — not the opposite one — contracts under the influence of the light 
fully as much (not visibly more) as it does during sleep in darkness 
more complete than the creature would experience in the field.’’ 
J. E. HARTING. 
cc 
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