World of the Dark 
meteors through the air, hovering for an instant over this 
blossom, probing into the sweet depths of another, and then 
dashing off again so quickly that the eye cannot follow them. 
My friend, Henry Pryer, had a great bed of evening primroses in 
his compound on the Bluff in Yokohama. Well I remember 
standing with him before the flowers, and, as the light began to 
fade upon the distant top of Fuji-no-yama, with net in hand 
capturing the hawkmoths, which came eagerly trooping to the 
spot. When it grew quite dark O-Chi-sari held a Japanese 
lantern aloft to help us to see where to make our strokes. A 
dozen species became our spoil during those pleasant evenings. 
Ah! those nights in Japan! Can I ever forget them ? 
Did you ever reflect upon the fact that the wings of many 
moths, which lie concealed during the daytime, reveal their 
most glorious coloring only after dark, when they are upon the 
wing ? Take as an illustration, the splendid moths of the great 
genus Catocala, the Afterwings, as we familiarly call them. The 
fore wings are so colored as to cause them, when they are 
quietly resting upon the trunks of trees in the daytime, to look 
like bits of moss, or discolored patches upon the bark. They 
furnish, in such positions, one of the most beautiful illustrations 
of protective mimicry which can be found in the whole realm of 
nature. The hind wings are completely concealed at such times. 
The hind wings are, however, most brilliantly colored. In some 
species they are banded with pink, in others with crimson; still 
others have markings of yellow, orange, or snowy white on a 
background of jet-black. One European species has bands of 
blue upon the wings. These colors are distinctive of the species 
to a greater or less extent. They are only displayed at night. 
The conclusion is irresistibly forced upon us that the eyes of 
these creatures are capable of discriminating these colors in the 
darkness. We cannot do it. No human eye in the blackness of the 
night can distinguish red .from orange, or crimson from yellow. 
The human eye is the greatest of all anatomical marvels, and the 
most wonderfu piece of animal mechanism in the world, but 
not all of power is lodged within it. There are other allied 
mechanisms which have the power of responding to certain 
forms of radiant energy to a degree which it does not possess. 
Let me commend to the study of my readers this world of the 
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