180 Chapter IV. 



quarters. The rapid increase of pseudogynes in that 

 colony, therefore, was in proportion to the number of 

 beetle-larvae which had successfully developed in the 

 same nest that year. 



It is, therefore, necessary to assume, that in san- 

 guinea colonies the frequent rearing of Lomechusa- 

 larvae gradually modifies the normal nursing instinct 

 of the ants. This modification is manifested partly by 

 the production of the crippled pseudogynes, partly by 

 the more appropriate treatment of the Lomechusa- 

 larvae which, after having been imbedded in their 

 cradles, remain undisturbed. Ants, therefore, grad- 

 ually learn to modify their nursing instinct. Is not 

 this a proof of intelligence ? True, their sensitive cog- 

 nition guiding their instinctive activities may furnish 

 the immediate occasion for that two-fold modification. 

 But we have proved in a former essay, in discussing 

 the different forms of learning, 1 that not every modi- 

 fication of the hereditary instinct, occasioned by sense- 

 experiences, is due to intelligence, but only that, which 

 manifests a knowledge of the appropriateness of a 

 given action. If ants were gifted with intelligence, 

 they could not help understanding, that by improving 

 their treatment of the Lomechusa-larvae, they cause 

 their colony but to perish the sooner, just as they con- 

 demn it to utter destruction by rearing pseudogynes. 

 The latter modification of the nursing instinct, which 

 leads to the rearing of cripples, can only be a 

 pathological symptom, pointing to a morbid dis- 

 turbance of the normal, organic condition of that 



*) "Die psychischen Faehigkeiten der Ameisen," p. Ill; "In- 

 stinct and Intelligence in the Animal Kingdom," Chap. 8. 



