ii THE NATURE OF INSTINCT 181 



ponines is intermediary in complexity between the 

 still rudimentary tendency of the humble bees and the 

 consummate science of the true bees ; yet there can be 

 no kinship between the bees and the meliponines. 1 

 Most likely, the degree of complexity of these different 

 societies has nothing to do with any greater or smaller 

 number of added elements. We seem rather to be 

 before a musical theme^ which had first been transposed, 

 the theme as a whole, into a certain number of tones, 

 and on which, still the whole theme, different variations 

 had been played, some very simple, others very skilful. 

 As to the original theme, it is everywhere and nowhere. 

 It is in vain that we try to express it in terms of any 

 idea : it must have been, originally, felt rather than 

 thought. We get the same impression before the 

 paralysing instinct of certain wasps. We know that 

 the different species of Hymenoptera that have this 

 paralysing instinct lay their eggs in spiders, beetles or 

 caterpillars, which, having first been subjected by the 

 wasp to a skilful surgical operation, will go on living 

 motionless a certain number of days, and thus provide 

 the larvae with fresh meat. In the sting which they 

 give to the nerve-centres of their victim, in order to 

 destroy its power of moving without killing it, these 

 different species of Hymenoptera take into account, so 

 to speak, the different species of prey they respectively 

 attack. The Scolia, which attacks a larva of the rose- 

 beetle, stings it in one point only, but in this point 

 the motor ganglia are concentrated, and those ganglia 

 alone : the stinging of other ganglia might cause death 

 and putrefaction, which it must avoid. 2 The yellow- 



1 Buttel-Reepen, &quot; Die phylogenetische Entstehung des Bienenstaates &quot; 

 (Biol. Centralblatt, xxiii., 1903, p. 108 in particular). 



2 Fabre, Souvenirs entomologiquet, 3 serie, Paris, 1890, pp. 1-69. 



