June 27, 1895J 



NATURE 



211 



a. 



session of olfactory organs. Vet there is among insects no one 

 specialised olfactory organ as among vertebrates ; for while there 

 is conclusive proof that this sense rests in the antenna; with many 

 insects, especially among Lepidoptera, there is good evidence 

 that in some Hymenoptcra it is localised in an ampulla at the base 

 of the tongue, while tlraber gives reasons for believing that in 

 certain Orthoptera (Hlattida;) it is located in the anal cerci and 

 the i)alpi, 



Hoiriiig. — In regard to the sense of hearing, the most casual 

 experimentation will show (and general experience confirms it) 

 that most insects, while keenly alive to the slightest movements 

 or vibrations, are for the most part deaf to the sounds which 

 affect us. That they have a sense of sound is equally certain, 

 but its range is very different from ours. A sensitive flame, 

 arranged for Liibbock by the late Prof. Tyndall, gave no response 

 from ants, and a sensitive microphone, arranged for him by I'rof. 

 Bell, gave record of no other sound than the patter of feet in 

 walking. But the most sensitive tests we can experimentally 

 apply may be, and doubtless are, too gross to adjust themselves 

 to the finer sensibilities of such minute, active, and nervous 

 creatures. There can be no question 'hat insects not only pro- 

 duce sounds, but receive the impression of sounds entirely 

 beyond our own range of perception, or, as Lubbock puts it, 

 that " we can no more form an idea of than we should have 

 been able to conceive red or green if 

 the human race had been blind. The 

 human ear is sensitive to vibrations 

 reaching at the outside to 38,000 in a 

 second. The sensation of red is pro- 

 duced when 470 millions of millions of 

 vibrations enter the eye in a similar 

 tin\e ; but between these two numbers 

 vibrations produce on us only the sen- 

 sation of heat. We have no especial 

 organ of sense adapted to them." It 

 is quite certain that ants do make 

 sounds, and the sound.i)roducing organs 

 on some of the abdominal joints have 

 been carefully described. The fact that 

 so many insects have the power of pro- 

 ducing sounds that are even audible to 

 us, is the best evidence that they 

 possess auditory organs. These are, 

 however, never vocal, but are situated 

 upon various parts of the body, or upon 

 different members thereof. 



Special Sense and Sense Organs. — 

 While from what has preceded it is 

 somewhat difficult to compare the more 

 obvious senses possessed by insects with 

 our own, except perhaps in the sense 

 of tf>uch. It is, I repeat, just as obvious 

 to the careful student of insect life that 

 they possess special senses which it is 

 difficult for us to comprehend. The 

 sense of direction, for instance, is 



very marked in the social Ilymenoptera which we have been 

 considering, and in this respect insects remind us of many 

 of the lower vertebrates which have this sense much more 

 strongly developed than we have. Indeed, they manifest more 

 es|K'cially what has been referred to in man as a sixth sense, 

 viz. a certain intuition which is essentially psychical, and which 

 undoubtedly serves and acts to the advantage of tlie species as 

 fully, perhaps, as any of the other senses. Lubbock demon- 

 strated that an ant will recognise one of its own colony from 

 among the individuals of another colony of the same species ; and 

 when we consider tliat the members of a colony number at times, 

 not thousands, but hundreds of thousands, this remarkable power 

 will be fully appreciated. 



The neuter Termites are blind, and can have no sense of light 

 in their internal or subterranean burrowings ; yet they will under- 

 mine buildings, and pulverise various parts of elaborate furniture 

 without once gnawing through to the surface ; and those species 

 which use clay, will fill up their burrowings to strengthen the 

 sup|iorts of structures which might otherwise fall and injure the 

 insects or betray their work. The bat in a lighted room, though 

 blinded as to sight, will fly in all directions with surh swiftness 

 and infallible certainly of avoiding concussion or coEilact, that 

 its feeling at a distance is practically incomprehensible to us. 



Telepathy. — But howeverdifticull itmaybe to define thisintuitive 



NO. 1339, VOL. 52] 



sense which, whileapparently combining some of the other senses, 

 has many attributes peculiar to itself, and however difficult it may 

 be for us to analyse the remarkable sense of direction, there can be 

 no doubt that many insects possess the power of communicating 

 at a distance, of which we can form some conception by what is 

 known as telepathy in man. This power would seem to depentl 

 neither upon scent nor upon hearing in the ordinary under- 

 standing of these senses, but rather on certain subtle vibrations 

 as difficult for us to comprehend as is the exact nature of elec- 

 tricity. The fact that men can telegraphically transmit sound 

 almost instantaneously around the globe, and that his very 

 speech may be telephonically transmitted, as cjuickly as uttered, 

 for thousands of miles, may suggest something of this subtle 

 power, even though it furnish no explanation thereof. 



The power f)f seml.-ling amongst certain moths, for instance, 

 especially those of llie family Bondiycida;, is well known to 

 entomologists, and many remarkable instances are recorded. I 

 am tempted to put on record for the first time an individual 

 experience which very well illustrates this power, as on a number 

 of occasions when I have narrated it most persons not familiar 

 with the general facts have deemed it remarkable. In 1863 I 

 obtained from the then Commissioner of .'\griculture. Colonel 

 Capron, eggs of Samia {ynthia, the Ailanthus silkworm of Japan, 

 which had been recently introduced by him. I was living in 



Flo. 3. — Some .'Vntennae of 

 Dendroides ; y, Dineutes 

 — .\ll greatly enlarged. 



Coleoptera : a, l.udius ; b, Corj'mbites ; t, Prinocyplion ; (/. .\cneus ; c, 

 g^ Lachnosterna ; k, Bolbocerus ; i, Adranes (after Le Conte and Horn). 



Chicago at the lime, and in my garden there grew two .Vilanthus 

 trees, which were the catise of my sending for the aforesaid eggs. 

 I had every reason to believe that there were no other eggs of 

 this species received in any part of the country within hundreds of 

 miles around. It seemed a good opportunity to lest the power 

 of this sembling, anil after rearing a number of larvx I carefully 

 watched for the ap]iearance of the first moths from the cocoons. 

 I kept the first moths separate, and confining a virgin female in 

 an improvised wicker cage out of doors on one of the -Vilanthus 

 trees. On the same evening I took a male to another part of the 

 city, and let him loose, having previously tied a silk thread 

 around the base of the abdomen to insure identificatiim. The 

 distance between the ca])tive female anil the released male was 

 at least a mile aiul a half, and yet the next morning these two 

 individuals were together. 



Now, in the moths of this family the male antenna- are 

 elaborately pectinate, the pectinations broad and each branch 

 minutely hairy (see Fig. 5, a.) These feelers vibrate incessantly, 

 while in the female, in which the feelers are less complex, there 

 is a similar movement connected with an intense vibration of the 

 whole body and of the wings. There is, therefore, everj' reason 

 to believe that the sense is in some way a vibratorj' sense, as, 

 indeed, at base is true of all senses, and no one can study the 

 wonderfully diversified structure of the antenna; in insects, 



