It is a wide-spread pest, with many relatives quite as bad as it is, and not only does it eat up the young and defenseless cucumbers and the roots of the corn, but it is the carrier of a germ infection of a serious nature to the cucumber. My friend, Dr. Erwin F. Smith, informs me that its kind has infested large areas in the South with this disease and dashed the hopes of thousands of boys who, instead of feasting on the melons they have planted with such care, must stand helplessly by and watch the leaves and flowers wilt and the vines decay. It must be remembered that this is a winged carrier of disease and anyone who still fails to understand the speed of travel of an epidemic had better watch the cucumber beetles busy spreading this destructive germ disease. A single beetle feeding on a diseased leaf can carry on its jaws enough germs to infect every melon or cucumber plant in a neighboring field, and that, too, in a single day. [Illustration] ONE OF THE SAWYERS (_Monohammus titilator_, Fab.) While standing on a street corner waiting for a street-car one day last summer my attention was attracted to this beautiful squirrel-gray creature at my feet. It was so evidently ill that, as I picked it up, I began to examine it to find out what was the matter. Clustered on its neck, out of reach of its feet or jaws were whitish bodies which evidently did not belong to its external skeleton but were probably the eggs of what I took to be some parasite whose growth within the body of the beast had brought about its pitiable condition. These are just visible between the creature's "horns" in the photograph. It was, in other words, a sick insect. It is because biologists see these parasites so plainly all down through the scale of living things that they are so sceptical of accepting any other cause of human disease until all possibility has been excluded of its being caused by some parasite or other, too small to be seen even by using the best microscopes. My sympathy for this long-horned beetle would be keener did I not read that its larval self is spent inside the wood of the pines and firs of our forests, doing great damage to them. When one is puzzled to know why any living thing should be burdened by such antler-like antennæ, let him remember the peacock's tail and the bird of paradise's plumage and be content to know that the laws of evolution are not yet fully known, and that, given time and growth, almost any form can be evolved. TWO-WINGED INSECTS (_Diptera_) Years ago in Berlin, my German landlady called me in as an expert to decide a controversy between her children and herself as to whether a frog had four legs or six. It seemed strange to me then that a grown-up woman should not know the number of a frog's legs. Yet there will be many who read these pages who do not know how many wings a fly has. And flies are much more important than frogs.