PREFACE TO THE SECOND EDITION. 



THE numerous observations of modern scientists, 

 illustrating the relations between the psychic life 

 of ants and of higher animals, have been extensively 

 utilized in preparing this second edition. We have 

 paid due regard to the observations and experiments, 

 published since 1897, on the differentiation of castes 

 in bee-hives. Besides, we have turned to account the 

 results of a statistical chart now completed, extending 

 over five years and comprising all the colonies of 

 Formica sanguinea in the neighborhood of Exaten, 

 Holland. This ant is the most interesting of all 

 European species. Thus we are able to publish many 

 new facts of interest in scientific biology regarding 

 the slave-making habits of this ant, its methods of 

 nest construction, its relationship to its guest 

 Lomechusa, and the influence of the latter in the 

 differentiation of castes in ant communities. Finally, 

 two additional illustrations of Lomechusa strumosa 

 and of its larva have been added in the text. 



