An early 20th century bug photography and fact book--the bugs had been recently killed and placed in lifelike poses, as the technology of the time didn't allow for photographing live and moving bugs in such detail. The results are good, most of them indistinguishable from the macro photography of our era. At the beginning of the book, the authors explain their methods. Later, they share their pictures and facts about the anatomies and behaviours of the insects and arachnids portrayed.
It is clear that both of the authors loved bugs and wished people to learn more about them and avoid killing them when possible, recognising their ecological significance but more so their importance to human life. Their views are more utilitarian than those of a modern invertebrate enthusiast--for example, they advocate the extinction of mosquitoes in areas where they're significant vectors of disease, as well as of insects detrimental to commercial crops--but that is to be expected from a book written in the 1910s. All in all a lovely historical document.