to favour the mutual approach of the animals, and enhance sexual excitement.[1]
In some moths—Bombyces and Noctuas—the sense of smell is developed to an extraordinary degree. "Sugar" can be found by the "Owl Moths" in the darkest night. Three female B. quercus, each in a cage of perforated zinc, were placed in a leather bag on a certain July 19th. On the 20th they were taken out. The bag had a sea-trip, but males continued to assemble to it for twelve days afterwards.[2] Even an empty pupa-case from which a female moth has escaped has been known to retain the attractive power for some time after the exclusion of the moth.[3] Clearly, these facts prove two things—that Lepidoptera possess the sense of smell, and that some species, at any rate, depend on this sense in "assembling." They are the foxhounds, as it were, in Lepidoptera; they course by scent, as undoubtedly butterflies and many Geometers find their mates by sight.[4]
In Java, according to Raffles, the Wild Pigs have so violent an aversion to the smell of urine, that the plantations are protected from their ravages by the practice of suspending rags impregnated with the fluid at small distances around the boundaries.[5] We do not understand, or rather cannot give an adequate reason, why the marine worm-like creatures Balanoglossus, long buried in the sand of the sea-shore, "exhale a peculiar odour resembling that of the chemical substance termed iodoform.[6] Again, the aquatic beetles Gyrinus, when handled, "give off a milky fluid of unpleasant odour from nearly all the joints of their body, but especially from the fore and hind edges of the thorax. The
- ↑ Semon, 'In the Australian Bush,' p. 160.
- ↑ J. Arkle, 'Entomologist,' xxvii. pp. 337.
- ↑ Cf. J.W. Tutt, 'British Moths,' p. 53.
- ↑ J. Arkle, 'Entomologist,' xxvii. pp. 337–8.
- ↑ 'History Java,' vol. i. p. 57.
- ↑ 'Roy. Nat. Hist.' vol. v. p. 573.—According to Mr. Bateson, as the disgusting smells emitted by various species of Balanoglossus may be thought to be protective, he tested various fishes with pieces of a single damaged specimen of B. salmoneus, which was dredged in Plymouth Sound. It was refused by both Mullet and Wrasse after trial, but was eaten by a Sole and by a Plaice ('Journ. Marine Biol. Assoc' (n.s.), vol. i. p. 247).
