PREFACE. 



monograph, which \vill, 1 hope, enable the student to form a rapid 

 acquaintance with our ant*, without recourse to the scattered and often 

 very meager descriptions that have hitherto served as the taxonomy of 

 the North American species. 



1 frankly admit that in writing the following pages I have endeav- 

 ored to appeal to several classes of readers to the general reader, who 

 is always more or less interested in ants ; to the zoologist, who cannot 

 afford to ignore their polymorphism or their symbiotic and parasitic 

 relationships; to the entomologist, who should study the ants if only 

 for the purpose of modifying his views on the limits of genera and 

 species, and to the comparative psychologist, who is sure to find in them 

 the most intricate instincts and the closest approach to intelligence 

 among invertebrate animals. Of course, the desire to interest so many 

 must result in a work containing much that will be dull or incompre- 

 hensible to any one class of readers ; thus the technical terms and 

 descriptions, which are full of significance to the entomologist, are 

 merely so much dead verbiage to the general reader, and the laboratory 

 zoologist, who shrinks at the mention of psychological matters, will 

 care little about ant behavior beyond its physiological implications. 



With the exception of the appendices and the first chapter, which 

 serves as an introduction, my account of the ants falls naturally into 

 two parts: a first, which is largely morphological, and comprises Chap- 

 ters II to X ; and a second, devoted to ethological considerations and 

 embracing the remaining chapters. To some it may seem that too much 

 space has been devoted to the relations of ants to other organisms and 

 to other ants (Chapters XVI-XXVII), but I justify my procedure on 

 the ground that this subject is the one in which I have been most inter- 

 ested, the one in which most advancement has been made within recent 

 years, and the one that has been fraught with the greatest differences 

 of interpretation. 



The series of appendices has been added largely as an aid to the 

 beginner in the study of myrmecology. The tables for the identifica- 

 tion of our North American ants are very incomplete, but could not 

 have been extended to embrace the species, subspecies and varieties, 

 and the different castes, as well as the genera, without unduly increas- 

 ing the size of the book. I hope to make good this defect in the mono- 

 graph to which I have alluded. In the meantime, I shall be glad to 

 identify ants for anyone who is interested in their study, especially if 

 the specimens are collected in America north of Mexico. The identi- 

 fication of such material serves a double purpose: that of increasing 

 our knowledge of the geographical distribution of our species, and of 

 spreading throughout the country collections of correctly identified 



