Lastly, we are told by Packard, in his _Guide to Insects_, that “Mr. Caleb Cooke, of Salem, who resided several years in Zanzibar, Africa, told me that the lantern-fly is said by the native to be luminous. They state that the long snout lights up in the night, and in describing it say its head is like a lamp (_keetchwa kand-tah_).” All this evidence appears to me to point in one way, and one way only—I mean, of course, in its entirety, since otherwise it points in two ways. But even if it is possible that in one country alone an insect—well known and conspicuous—can have got the reputation of being luminous without really being so, at least occasionally, this can hardly have come about in regard to the same, or some allied insect, in three or four countries. Added to this we have Madame Merian’s direct evidence, but, on the other hand, it is perfectly clear that these insects are not always, or even generally, luminous. The conclusion, then, seems irresistible that they occasionally are so, that, for some reason or other, the phosphorescent principle is active in them only at certain times or seasons. Why this should be so we do not know, but there is nothing inconceivable in it; and some other animals—for instance, centipedes—would seem to be luminous at some times and not at others. The so-called lantern or snout being a very remarkable organ, for which some use must be assumed, the likelihood of its sometimes becoming a lamp would be increased considerably, if, so far as we knew, it performed no other office. This was how the case stood till lately; but in 1899 there was the Skeat Expedition for scientific purposes to the Malay Archipelago, and on its return Mr. Nelson Annandale propounded a theory in regard to the more ordinary use, at least, of the organ in question, which was based on his own observation. His account is as follows: “The curious anterior prolongation of the head in many genera of the _Fulgoridæ_ has long puzzled entomologists. At Biserat, in Jalor, I was fortunate enough to observe the real use of this peculiar structural modification. On the morning of May 30th I noticed a specimen of _Hotinus spinola_ seated on the trunk of a Durian tree in the village, and incautiously attempted to catch it in my hand. The insect remained almost still, merely drawing in its legs towards its body and pressing the claws firmly against the bark, until I had almost touched it. Then it lowered its head with very great rapidity, flew up into the air without spreading its wings, and alighted on the roof of a house six feet behind a tree, and considerably higher than its position on the trunk had been. At the time I did not notice anything peculiar in the way in which this _Fulgorid_ jumped, for there are many large species of the same family which, without being provided with long noses, can leap for a considerable distance by means of their legs only; but as I was examining my specimen (a dead one) I was struck by an indentation or