the introduction discusses the value of this assembled information and offers suggestions for future study. No longer are cockroaches regarded only as disagreeable pests; many species appear to be important, actually or potentially, as carriers of disease. Recognition of this importance has grown considerably, even in the period since World War II. Consequently, anything that increases our knowledge of the basic bionomics of cockroaches will be consulted widely for factual information and for clues to new approaches.

In spite of this extensive compilation, the limitations of present information about cockroach bionomics must be kept in mind. The cited observations of many writers were fragmentary, or their conclusions disagreed. But it is fundamental to scientific inquiry that we should know and attempt to evaluate the results of previous study, and that is what Drs. Roth and Willis have done. Fortunately, their review is readily available. Sometimes, a piece of work fails to be of maximum value because the results are not generally accessible to later students. For this reason I am especially glad that the Smithsonian Institution, by disseminating the results of the authors' labors, has this opportunity to exercise one of its traditional functions—that of diffusing knowledge.

Throughout the period of research by Drs. Roth and Willis at Natick, I was in frequent correspondence with them, and I admire their many accomplishments. Our warmest commendations should go not only to them personally but also to those in administration who encouraged their fundamental research and who aided in the financial support of this publication.

Ashley B. Gurney                   
Entomology Research Division         
United States Department of Agriculture  

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