OUR SIX-FOOTED RIVALS. 205 



companions. The manner in which, when on the march, they are 

 directed by their officers, and the promptitude and precision with 

 which a column is sent out to seize any booty indicated by scouting- 

 parties, show likewise a completeness and precision of language very 

 different from anything we observe in quadrupeds and birds. 



But as to the nature of this language, which Mr. Belt rightly calls 

 " wonderful," we are as yet very much in the dark. Sounds audible 

 to our ears they scarcely can be said to emit. Their principal organs 

 of speech are doubtless the antennas : with these, when seeking to 

 communicate intelligence, they touch each other in a variety of ways. 

 There can be no doubt that, with organs so flexible and so sensitive, 

 an interchange not merely of emotions but of ideas must be easy. 



But there is another channel of communication which deserves to 

 be carefully investigated. We know that the language of vertebrates, 

 or at least of their higher sections, turns on the production or recog- 

 nition of sounds. What if the language of social insects should be 

 found to depend, in part at least, on the production and recognition 

 of odors ? We have already full proof that their sense of smell is de- 

 veloped to a degree of acuteness and delicacy which utterly passes 

 our conceptions of possibility, and to which the scent of the keenest 

 hound presents but a very faint aj^proximation. Collectors of Lej)i- 

 doptera are well aware that if a virgin female moth of certain species 

 is inclosed in a box, males of the same species will make their ap- 

 pearance from distances which may be relatively pronounced pro- 

 digious. As soon, however, as the decoy has been fecundated, this 

 attraction ceases. This is only one among the many jihenomena 

 which testify to the wonderful olfactory powers of insects. So much, 

 then, for the recognition of odors. Nor is their production among in- 

 sects a matter open to doubt. Scents, distinctly perceptible even to 

 our duller organs, are given off by many. The pleasant odor of the 

 musk-beetle, and the offensive smells of the ladybirds, the common 

 ground-beetles, the oil-beetles, the Spanish fly, and the " devil's coach- 

 horse" hence technically named Gceriits olens are known to every 

 tyro in entomology. The next question is, Are these odors at all 

 under the control of the insect, and capable of being produced, sup- 

 pressed, or modified at will ? We have noticed many instances where 

 the odors of insects became more intense under the influence of anger 

 or alarm. A peculiarly pungent odor is said to issue from a beehive 

 if the inmates are becoming excited. 



The possibility of a scent-language among insects must therefore 

 be conceded. Mr. Belt thinks that the Ecitons mark out a track which 

 is to be followed by their comrades by imparting to it some peculiar 

 odor. He says: "At one point I noticed a sort of assembly of about 

 a dozen individuals that appeared in consultation. Suddenly one ant 

 left the conclave, and ran with great speed up the perpendicular face 

 of the cutting without stopping. It was followed by others, which, 



