TABLE OF CONTEXTS. xxv 



PAGE 



IV 7 . Observations Supposed to Indicate the Existence of Rea- 

 soning in Ants 540 



V. Conclusion. The Relations of Plastic to Instinctive Behavior 543 



APPENDICES. 



A. Methods of Collecting, Mounting and Studying Ants 545 



B. Key to the Subfamilies, Genera and Subgenera of the North 



American Formicidse, for the Identification of the Workers 557 



C. A List of Described North American Ants 561 



D. Methods of Exterminating Noxious Ants 573 



E. Literature 578 





