202 ANIMAL INTELLIGENCE. 



struction that the main beams, the sudden breakage of which 

 would threaten the whole building and themselves therewith, 

 are either spared, or else so fastened together again with a ce- 

 ment made out of clay and earth that their strength is greater 

 than ever ! (?) Hagen also states that they never cut right 

 through the corks which stop up stored bottles of wine, but 

 leave a very thin layer, which is sufficient to prevent the out- 

 flow of the wine and the consequent destruction of the workers. 

 The same author relates that in order to reach a box of wax 

 lights they made a covered road from the ground up to the 

 second story of a house. 1 



It is needless to give a special description of any of 

 the other habits of these insects, such as their swarming, 

 breeding, &c., for they all more or less closely resemble 

 the analogous habits of ants and bees. It is very remark- 

 able that insects of two distinct orders should both 

 manifest such closely similar social habits of such high 

 complexity, and it rather surprises me that more has not 

 been made of this point by writers opposed to the 

 principles of evolution. Of course if the point were 

 raised, the argument in answer would require to be, either 

 that the similar instincts were derived from common and 

 very remote progenitors (in which case the fact would form 

 by far the most remarkable instance of the permanency 

 of instincts among changing species), or more probably, 

 that similar causes operating in the two orders have 

 produced similar effects complex and otherwise unique 

 though these effects undoubtedly are. 



In connection with the theory of evolution I may 

 conclude this chapter with the following quotation from 

 Smeathman, as it shows how natural relation may develop 

 for the benefit of the species instincts which are detri- 

 mental to the individual. Speaking of the soldiers he 

 says : 



I was always amused at the pugnacity displayed when, in 

 making a hole in the earthy cemented archway of their covered 

 roads, a host of these little fellows mounted the breach to cover 

 the retreat of the workers. The edges of the rupture bristled 

 with their armed heads as the courageous warriors ranged 



1 Geistesteben der TMere, pp. 194 and 199-200. 



