It were supererogation to point out to a body of this kind the value of the most careful and thorough work in connection with life histories and habits, often involving as it does much microscopic study of structure.  The officers of our institutions who control the funds, and more or less fully our conduct, are apt to be somewhat impatient and inappreciative of the time given to anatomic work, and where it is given for the purpose of describing species and of synopsizing or monographing higher groups, without reference to agriculture, I am firmly of the belief that it diverts one from economic work, but where pursued for a definite economic purpose it cannot be too careful or too thorough and I know of no instances better calculated to appeal to and modify the views of those inclined to belittle such structural study than Phylloxera and Icerya.  On the careful comparison of the European and American specimens of Phylloxera vastatrix, involving the most minute structures and details, depended originally those important economic questions which have resulted in legislation by many different nations and the regeneration of the affected vineyards of Europe, of our own Pacific coast, and of other parts of the world by the use of American resistant stocks.  In the case of Icerya purchasi the possibilities of success in checking it by its natural enemies hung at one time upon a question of specific difference between it and the Icerya sacchari of Signoret—­a question of minute structure which the descriptions left unsettled and which could only be settled by the most careful structural study and the comparison of the types, involving a trip to Europe.

CONCLUSION.

I have thus touched, gentlemen, upon a few of the many subjects that crowd upon the mind for consideration on an occasion like this—­a few gleanings from a field which is passing rich in promise and possibility.  It is a field that some of us have cultivated for many years and yet have only scratched the surface, and if I have ventured to suggest or admonish, it is with the feeling that my own labors in this field are ere long about to end and that I may not have another occasion.

At no time in the history of the world has there, I trow, been gathered together such a body of devoted and capable workers in applied entomology.  It marks an era in our calling and, looking back at the progress of the past fifteen years, we may well ponder the possibilities of the next fifteen.  They will be fruitful of grand results in proportion as we persistently and combinedly pursue the yet unsolved problems and are not tempted to the immediate presentation of separate facts, which are so innumerable and so easily observed that their very wealth becomes an element of weakness.  Epoch-making discoveries result only from this power of following up unswervingly any given problem, or any fixed ideal.  The kerosene emulsion, the Cyclone