Science-gossip . Fig. 5. Anterior Thoracic Spir.^cle of Musca romiioria. sensation ; but what sense they represent is verydifficult to prove from experiment, because anotherquite different sense-organ is intermingled withthem. It is highly probable that they are tactile,though this term is very vague, for it implies thesuggestion of either cold or heat, humidity ortouch, etc. ; therefore further proof is most highly developed tactile hairs are those. Fig. 6. Posterior Thoracic Spiracle op Musca eomitoria •on the lobes of the proboscis, where they end in alarge bulb in immediate con
Science-gossip . Fig. 5. Anterior Thoracic Spir.^cle of Musca romiioria. sensation ; but what sense they represent is verydifficult to prove from experiment, because anotherquite different sense-organ is intermingled withthem. It is highly probable that they are tactile,though this term is very vague, for it implies thesuggestion of either cold or heat, humidity ortouch, etc. ; therefore further proof is most highly developed tactile hairs are those. Fig. 6. Posterior Thoracic Spiracle op Musca eomitoria •on the lobes of the proboscis, where they end in alarge bulb in immediate connection with the their position they are, doubtless, organs oftouch. In a well-distended proboscis cut ver-tically they are very distinct. Another featurewell developed in the third joint of the antennaeof the blow-fly and many of the domestic species is£L somewhat spiral organ coveied on the exteriorwith fine unpigmented hairs. These hairs penetratethe walls of the organ, which is also lined on theinterior surface with epithelium, and receive a richsupply of nerve-fibres. It is computed that thereare about eighty of these organs in one antenna ofthe blow-fly, and from their position and the well-known highly-developed sense of smell possessedby this insect there can scarcely be a question thatthey are other than olfactory. The extreme paucityof these organs in other species of different habitsstrengthens my conviction. (To be continued.) KAL
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