ANIMAL SENSE PERCEPTIONS. 171 



to favour the mutual approach of the animals, and enhance 

 sexual excitement.* 



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. f 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.J Clearly, these facts prove two things — that Lepi- 

 doptera possess the sense of smell, and that some species, at any 

 rate, depend on this sense in " assembling." They are the fox- 

 hounds, as it were, in Lepidoptera ; they course by scent, as un- 

 doubtedly butterflies and many Geometers find their mates by 

 sight.§ 



In Java, according to Baffles, the Wild Pigs have so violent 

 an aversion to the smell of urine, that the plantations are pro- 

 tected from their ravages by the practice of suspending rags im- 

 pregnated with the fluid at small distances around the boundaries. || 

 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.1T 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. 



f J. Arkle, ' Entomologist,' xxvii. pp. 337. 



J Cf. J. W. Tutt, ' British Moths,' p. 53. 



§ J. Arkle, ' Entomologist,' xxvii. pp. 337-8. 



[| ' History Java,' vol. i. p. 57. 



H ' Boy. Nat. Hist.' vol. v. p. 573. — According to Mr. Bateson, as the dis- 

 gusting smells emitted by various species of Balanoglossios 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). 



