THE SMELLING-OKGANS OF INSECTS. 69 



Structure, conducted tlirough a ceutury by some of our most distin- 

 guished scientists, we are utterly unable to point out with positive 

 certainty the precise location and nature of the organs of smell. Natu- 

 ralists have differed and still differ in their views in regard to their 

 location. Cuvier, Audouiu, Dumeril, and Burmeister, have regarded 

 tlie spiracles, or breathing-pores, as discharging this office. Reaumur, 

 Lyonnet, Latreille, and others, have referred it to the antennse. 

 Others have believed that tiie palpi were the true smelling organs, and 

 others that the sense belonged to certain cavities in the front part of 

 the head, and to the mucous lining of the mouth; while Kirby and 

 Spence have thought that they have discovered a nose in the fore-part 

 of the head, which they call the rliinarium or nostril-piece, connected 

 with which is a beautifully-striated structure, which they have de- 

 scribed as the veritable organs of smell.* 



Although we do not surely know the positiou and structure of these 

 organs, their existence is beyond a doubt. If a decaying carcass be 

 concealed beneath a sod oi other cover, carrion beetles, in their sea- 

 son, may soon be seen hovering over it, seeking it as a nidus for their 

 eggs. I have seen swarms of flesh-flies, CalUphora vomitoria and Lu- 

 cilia Cce&ar, drawn to the disgusting odor of the " stinkhorn " fungus, 

 Phallus impndicus,vfh\oh so perfectly counterfeits that of decaying flesh. 



Collectors of Nocturnal Lepidoptera know the readiness with which 



*I am indebted to Dr. Hagen, of Cambridge, Jlass., for the following information as to 

 the location of these organs, drawn from Hauser ; ZeiUchrift, f. Wissenschaft, Zoologie, 

 1880, and giving the latest observations of the best investigators . — 



Strong smelling substance, as turpentine, carbolic acid and decayed meals, proved that 

 the organs of smell were situated in the antennae in very many insects. Nevertheless, 

 not all the insects employed in the experiments were deprived of the sense after the 

 amputation of the antennae, among which were Carahus, PyvrhocorU, etc. After the an- 

 tennse were cut, the males rarely mated. 



Sensitive bristles are present in Orthoptcra {CEdipoda and Oaloptenus) on every joint of 

 the antennae after the eighth or ninth, and fifty sensitive pits or furrows, which are 

 probably closed by a fine membrane and have interiorly one smelling-rod. Sienobothrus 

 and Gryllotalpa are similarly provided. Diptera have in the third joint from 100 to 200 

 furrows, with as many as 200 sensitive bristles. Vanessa has on each joint of the knob of 

 the antennae, fifty furrows. Of the Coleoptera, the Carabids, Cerambycids and Curcu- 

 lionides, possess no antennal furrows, while they are present in the Silphides, Staphy- 

 linides and Tenebrionides. The Lamellicornes have on the underside an immense number 

 of very small furrows, viz.: in the female 17,500, and in the male 39,000. 



All insects which have to rely upon the sense of smell for discovering their food or 

 placing their eggs, possess many sensitive furrows or pits in the antennae, as bees, wasps, 

 ichneumons, Diptera and Lepidoptera. 



Dr. Hagen suggests that probably in many insects the organs of smell smd taste are 

 united. Such may be the organs which are found in the honey-bee in the epipharynx (on 

 imderside of the labrum), consisting of numerous sensorial furrows or channels and con- 

 nected interior structure, and which have just been discovered in the same position in 

 Pemphigus and Cicada, by Prof. H. Osborn, of the Iowa State Agricultural College (See 

 Canadian Entomologist^ .\iv, 1882. p. 64). 



