The publisher may, perhaps, be allowed to call the reader's attention to the illustrations--particularly to the two of the Sand-Wasps, reproduced in colour. The difficulties of photographing from wild life active creatures of such small dimensions as hymenopterous insects are very great from an optical standpoint. The picture of Spinipes bringing the beetle grub to her tube took several years to accomplish successfully, and the strain involved by the conditions, a blazing June sun on the operator's back, an uncertain foothold, and the necessity of keeping the attention riveted for hours on one particular patch of sunlit sand, was exceptional. It is of course possible, probable even, that with the introduction of an improved lens system, which will enable fast exposures to be made at very short range on minute moving objects, this particular picture may be repeated and improved upon. But the odds against the second picture on the same page, that of Spinipes stinging the jewel-fly, _ever_ being repeated, are enormous. It will be necessary in order to secure the repetition of such a picture, first, that the camera shall be focussed on one out of a score of tubes; second, that the parasitic jewel-fly shall enter that particular tube; third, that the Owner Wasp shall return while the jewel-fly is below; fourth, that the Owner Wasp shall pull the jewel-fly to the surface; fifth, that the jewel-fly shall cling to the rim of the tube; sixth, that the Wasp shall sting it in this position--it will be noticed that the sting is directed at the junction of the thorax and abdomen; seventh, that the observer shall be ready to expose his plate at the exact psychological moment; and eighth, that he shall succeed in doing so. The first six conditions were, in Mr. English's case, fulfilled by chance. As regards the seventh he was unready. He was, in fact, some feet below his camera. But chance befriended him still further. He caught the jewel-fly's glint, and caught the shadow of the returning Wasp. He flung his arm up, grabbed the dangling bulb, and pressed at random. This action dragged the camera from its moorings--to fix a camera on a Sand Cliff's side is no slight task--and it fell twelve feet down. Yet it had done its work and made the picture. There are a score of pictures in this book, which are believed to be unique, not only by reason of the rarity of their subjects, but also by reason of the fact that they are the _only_ pictures of such subjects, good or bad, in existence. The most remarkable among them is the picture of Spinipes stinging the jewel-fly. INTRODUCTION I know a Boy Scout who has never seen a weasel. Many weasels, I fancy, must have seen that Boy Scout. And I know a Girl who has never seen a Harvest Mouse, but who might have, often. There may be other boys and girls like these. There may be grown-ups also. It is for them that I have written this book. It is to them that I offer its pictures.