It is spring, early spring, and already the young Aphides have begun, with gladness born of the opening year, to absorb the sweet sap from the stems of the immature wheat-crop. Later, however, when July’s sun shines brightly behind its cooling screen of clouds—for in England all climatic extremes are tempered—they ascend in “numbers numberless” to attack the ear itself. What, then, can save the hope of the husbandman? What but _Ephedrus plagiator_, a small black-winged Ichneumon Fly that even now is at work? As each individual Aphis clings to the wheat, it becomes, in spite of its efforts to fill itself, hollower and hollower; its appetite flags, and ere it can fatally affect the plant on which man’s life and the machinations of the protectionist depend, it has become a mere brown pupa-case for a body other than its own to develop in. A day or two, and almost on every grain of the wheat hangs an insect, lifeless, but—oh, floweret springing from the tomb!—life-filled. Hardly a living Aphis is to be seen feeding amongst them. The wheat-crop has been saved. But the march of events, thus unfolded, does not end here. Another drama has to be played out ere the full life issues from the once living cradle whose contents it has absorbed and become, nor will it bear the image of that particular Ichneumon Fly that laid its little egg, some weeks ago, in the body that seemed so designed for it. Like the Aphis, the Ichneumon, too, must learn to live for others, thus rising through selfishness to a purer and higher embodiment. If we pass a little later through the same cornfield, another insect, differing from, yet of the same general type as the prior parasite, may be seen running to and fro over the wheat-ears, tapping each tenanted abode with tremulously quivering antennæ, which, as well as the whole body, seem to vibrate with excitement. It is looking for lodgings, but not every house so touched can be utilised, for _Ceraphrus Carpenteri_—such is the new tenant’s name—must first be satisfied that none of its own species have already taken possession. Once assured on this point, however, its duty lies plain before it, and bending its antennæ against the wheat-ear, so as to form a fulcrum, it turns the tip of its abdomen towards that of the dead Aphis, and with its ovipositor commences to saw through the skin. As much as ten minutes may be occupied in the accomplishment of this task, for the sarcophagus that has thus to be pierced is hard, and the ovipositor, though short, is not stout, but slenderly formed. But there is no flagging of energy, and at length, when efforts steadily continued have been crowned with success, the same deft instrument is again employed to pierce the sleeping _ephedrus_, and a second egg is deposited in this second cradle. To this new tenant the former one must now yield up the juices of its body, even as those of the Aphis were freely rendered unto it. It must die in its turn, but by its death