THE BAY OF BUTTERFLIES 261 
may be equal. But the irresistible maelstrom im- 
pels only the males. Whence they come or why 
they go is as utterly unknown to us as why the 
females are immune. 
Once, from the deck of a steamer, far off the 
Guiana coast, I saw hosts of these same great saf- 
fron-wings flying well above the water, headed 
for the open sea. Behind them were sheltering 
fronds, nectar, soft winds, mates; before were cor- 
roding salt, rising waves, lowering clouds, a 
storm imminent. Their course was NNW, they 
sailed under sealed orders, their port was Death. 
Looking out over the great expanse of the Ma- 
zaruni, the fluttering insects were usually rather 
evenly distributed, each with a few yards of clear 
space about it, but very rarely—I have seen it 
only twice—a new force became operative. Not 
only were the little volant beings siphoned up in 
untold numbers from their normal life of sleep- 
ing, feeding, dancing about their mates, but they 
were blindly poured into an invisible artery, 
down which they flowed in close association, 
véritables corpuscules de papillons, almost touch- 
ing, forming a bending ribbon, winding its way 
seaward, with here and there a temporary fray- 
ing out of eddying wings. It seemed like a way- 
