and of several other Animals. 299 



^, In the other example which I have to adduce, the cir- 

 cumstances were in some measure the reverse. It was in a room 

 where the sun shone, but the head of the cat was turned to- 

 ward one of the corners, and I Jook€d at it myself in such a man- 

 ner as not to receive either the direct rays of the sun, or the 

 light directly reflected. Here the eye of the animal received 

 much more light than in the other example, and transmitted 

 more to me, but my eyes receiving more light from another di- 

 rection, and being on this account less sensible to it, the eyes of 

 the cat did not appear so shining. 



Valmont de Bomare, in the article Chat of his Dictionary, 

 (the edition in 15 vols.), says, after what we have already quoted, 

 " it seems that the lustre, the splendour, which is observed in 

 the day time in the eyes of the cat, comes from the shining part 

 of the retina, at the place where it surrounds the optic nerve." 

 This does not agree very well with what precedes ; for in full 

 day-light the retina of the cat is not visible, and if he means to 

 speak of the lustre that is visible in a weak light, it is certainly 

 of the same nature as that which is observed in darkness, and 

 which Valmont de Bomare attributes to the imbibing of the light 

 of day. Nor does this author speak here from his own observa- 

 tion : what he says of the eyes of the cat is taken almost word 

 for word from Buffon''s works, and from the first edition of the 

 Encyclopedic. We also find in the Geneva edition of 39 vols. 

 4to, article Chat^ the following words : " It appears that the 

 lustre, the shining, the splendour, which are observed in the 

 eyes of the cat, come from a sort of velvet, which lines the bot- 

 tom of the eye, or from the shining of the retina at the place 

 where it surrounds the optic nerve.'" The phenomenon can be 

 imitated with all its peculiarities, by placing bits of tinsel under 

 suitable circumstances, or by other similar means. It is not 

 therefore necessary to have recourse to phosphorescence for an 

 explanation of it. 



It is certain enough, that a great number of substances become 

 luminous in the dark, after having been exposed some moments 

 to the light of the sun, or only to the ordinary day-light, or to 

 the light of a lamp, or of the moon. But it is not probable that tlie 

 eyes of the cat are of this class ; for, like those of other animals, 

 they are filled with various humours ; and there results from M. 



