The state of health of a hawk may be ascertained by various signs, more or less infallible. Mutes, castings, and the general demeanour furnish the most obvious symptoms; but the books, which bestow a vast amount of attention upon the two former, are much too silent as to the latter and more subtle indication of an incipient malady. The falconer should always observe the colour of every hawk's mutes. If she is kept for any long time at a stretch upon a screen-perch under which the sawdust or sand is so thickly strewn as to absorb them altogether, a piece of paper must be placed occasionally under the perch, which will enable him to make the necessary inspection. And at the first appearance of anything wrong the proper remedy should be applied. The mutes of a hawk in good health should be of an almost uniform bright white colour, and of the consistency of the whiting with which a lawn-tennis ground is usually marked out. If there are specks of black in them there is no cause for alarm, but these should not be abundant or large in size. If any other colour is to be seen there is something amiss; and if the mutes are either watery or too thick the hawk is not in proper health. The sooner these symptoms are detected and the right steps taken the easier will be the cure; and in most cases a diet of freshly-killed birds given in moderation twice a day will set matters right without any resort to strong measures. If, however, the discoloration is great, and appears suddenly, a dose should be at once given before the sufferer loses her appetite and becomes unable to retain food or anything else in her crop. Castings are easily found under the perch or round the block, though when hawks are tied very near to one another on the same screen-perch it is sometimes difficult enough to know which of them has thrown a casting which is picked up between her and her neighbour. The appearance of them should always be noticed before they are thrown away. They should be more or less egg-shaped and compact, with no great amount of oily matter adhering to the outside. The colour should be rather darker than that of the feathers, fur, wool, or whatever else has been taken to form the casting; and if it is not so, it is a sign that the crop is foul. A hawk in good health should also cast within a reasonable time after the casting has been swallowed; and otherwise you may suspect that the gorge is clogged. A hawk which has been fed late even in a summer evening should throw up her casting before eight at latest on the following morning. When a hawk is slow at casting, she should be carried a bit, and will then often cast on the fist, or immediately upon being put off it on to the block. A wild merlin will often eat the whole of a small bird between 8 and 9 a.m., put it over by about 2 p.m., cast, and then begin to look out for the evening meal.