26 VIGNETTES FROM NATURE. 



tuberose, and night-flowering cereus. Some 

 of them actually close up during the day, and 

 most of them emit their perfume only in the 

 evening when the moths on which th%y 

 depend for fertilisation are abroad. Moths, 

 indeed, hunt mostly by smell, though they are 

 also partly guided by sight, and perhaps 

 even in part by the faint phosphorescence, 

 hardly visible to human eyes, which, as the 

 daughter of the great Linnaeus first observed, 

 plays lambent over certain of their favourite 

 blossoms in the early shades of night. I 

 have seen this phosphorescence myself (or 

 fancied I saw it) on the petals of the evening 

 primrose; but -only a few people have weak 

 enough vision to detect it, for, like negative 

 images, it cannot be seen by persons of 

 robust and vigorous sight. Women and 

 artists perceive it oftener than men of science, 

 which no doubt tells rather hardly against 

 its objective reality. Yet perhaps they and 

 the moths can see some things which are 

 hidden from the wise and learned ; at least, 



