PREFACE.
This volume had its inception in a series of eight lectures delivered at Columbia University during the spring of 1905, and represents, in a much condensed form, the results of a decade of uninterrupted study of the Formicide, and of the works that have been written on these insects.
If an excuse were required for its publication, one might be found in the fact that for many years no comprehensive treatise on the ants has appeared in the English language. This may be regarded as a reproach to English and American zoölogists, since during all this time almost the only active contributors to myrmecology were to be found on the European continent. It must be admitted, however, that the methods of publication adopted by continental writers have not been such as to attract the attention of English-speaking students, since their works have not only been issued in a variety of languages—French, German, Swedish, Italian, Russian, etc.—but also in a great number of often very obscure, local or inaccessible journals and proceedings of learned societies. Moreover, most of the continental observers within recent years have been too busty with special lines of investigation to publish compendia on myrmecology. It thus happens that although ants are our most abundant and most conspicuously active insects, they have not, till very recently, received any serious attention from American systematists, and the descriptions of most of our species must still be sought in a lot of more or less fragmentary foreign contributions.
My work began in an endeavor to increase our systematic knowledge of the North American ants, but I was fascinated by the activities of these insects and soon saw the advantage of studying their taxonomy and ethology conjointly. This method, which was, indeed unavoidable, has greatly retarded the appearance of the present work, for it was impossible to write about the behavior of many of our most interesting forms till their taxonomic status had been definitely settled. On the other hand, I could find no satisfaction in devoting all my energies to collecting and labelling specimens without stopping to observe the many surprising ethological facts that were at the same time thrusting themselves upon my attention. My observations have now covered so much our fauna that I shall soon be able to publish a systematic
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