Book excerpt: As an outgrowth of earlier work done on the genital structures of male Mutillid wasps, the author's conviction that the biology of insects is as much a factor in their taxonomy and phylogeny as morphology led him to assemble all the knowledge regarding their biology and to carry on some minor researches that were included in Part 1 of this bulletin. He reviewed 630 references, listed in the bibliography and undertook a study of the genotypes of the family, reporting the results in Part 2. This bulletin provides descriptions of multiple specimens examined.