It was across this maze of leafage, and in absolute darkness, that the butterflies had to find their way in order to attain the end of their pilgrimage.
Under such conditions the screech-owl would not dare to forsake its hollow in the olive-tree.

The butterfly, better endowed with its faceted eyes than the owl with its single pupils, goes forward without hesitation, and threads the obstacles without contact.

So well it directs its tortuous flight that, in spite of all the obstacles to be evaded, it arrives in a state of perfect freshness, its great wings intact, without the slightest flaw.

The darkness is light enough for the butterfly.
Even if we suppose it to be sensitive to rays unknown to the ordinary retina, this extraordinary sight could not be the sense that warns the butterfly at a distance and brings it hastening to the bride.

Distance and the objects interposed make the suggestion absurd.
Moreover, apart from illusory refractions, of which there is no question here, the indications of light are precise; one goes straight to the object seen.