HISTORY OF 



same conformation of that organ ; and though, 

 like us, they cannot see in a total exclusion of 

 light, yet they are sufficiently quick-sighted at 

 times when we remain in total obscurity. In the 

 eyes of all animals nature hath made a complete 

 provision, either to shut out too much light, or to 

 admit a sufficiency, by the contraction and dila- 

 tation of the pupil. In these birds the pupil is 

 capable of opening very wide, or shutting very 

 close : by contracting the pupil, the brighter 

 light of the day, which would act too powerfully 

 upon the sensibility of the retina, is excluded ; by 

 dilating the pupil, the animal takes in the more 

 faint rays of the night, and thereby is enabled to 

 spy its prey, and catch it with greater facility in 

 the dark. Beside this, there is an irradiation on 

 the back of the eye, and the very iris itself has a 

 faculty of reflecting the rays of light, so as to 

 assist vision in the gloomy places where these 

 birds are found to frequent. 



But though owls are dazzled by too bright a 

 day-light, yet they do not see best in the darkest 

 nights, as some have been apt to imagine. It is 

 in the dusk of the evening, or the grey of the 

 morning, that they are best fitted for seeing at 

 those seasons when there is neither too much 

 light, nor too little. It is then that they issue 

 from their retreats to hunt or to surprise their 

 prey, which is usually attended with great suc- 

 cess ; it is then that they find all other birds 

 asleep, or preparing for repose, and they have 

 only to seize the most unguarded. 



