Wild hawks vary a good deal in the date at which they drop their first feather, but trained hawks can be made to vary still more. Experience soon showed that a certain diet and regimen would hurry on the moult and expedite its progress, whereas another would defer and protract it. The young falconer will reflect betimes which of these treatments will best suit his plans, and act accordingly, remembering that, having once decided, he cannot without great inconvenience and even some risk adopt a different system. In any event he will, except in the case of rook-hawks, find himself in some difficulty, for the moulting process is in any case a long one. It is reckoned by months rather than by weeks. In peregrines, which are notoriously slow and bad moulters, it may last a half-year. If ever it is completed in three months the falconer may think himself lucky; and the worst of it is, that the moulting months generally include August and September. The earliest day on which a feather can be dropped is usually well on in March or often early in April, and this is in the case of eyesses, for the passage hawks can hardly be induced to begin till a good deal later. Unless, therefore, the falconer can hurry the feathers down, he will hardly get his hawk even through the moult, and far less ready for active work, by September 1. We shall see, moreover, that the faster the moulting process is pushed on the less fit will the hawk be at the end of it to immediately take the field. It is thus, in at least nine cases out of ten, practically impossible to fly a hawk in full plumage at rooks in the spring, and afterwards to fly the same hawk also in full plumage at game in August or September. And whether she has been flown in the early part of the year or not, it is still almost equally difficult to so arrange that she shall fly in full feather in the early part of the game season. Hence it is that an eyess of the year, when flown as soon as she is fully trained, comes usually into the field better equipped in the way of feathers than what may be called her elders and betters. Occasionally the moult of a passage hawk, or even adult eyess, can be deferred until August or even September, but this result is not to be reckoned upon with any certainty. The youthful grouse or partridges and their rather hard-worked parents, the adolescent or moulting lark, and inexperienced blackbird, ought all to be a little grateful to Dame Nature for having ordained that they should be pitted against hawks which are either young themselves or else have to take the air with shortened sail.