Several of the forms of paralysis have each its significant gait. For instance, if a patient comes in with a firm, rather precise, calculated sort of gait, "clumping" each foot upon the floor as if he had struck it an inch sooner than he had expected, and clamping it there firmly for a moment before he lifts it again, as though he were walking on ice, with more knee action than seems necessary, you would have a strong suspicion that you had to deal with a case of _locomotor ataxia_, in which loss of sensation in the soles of the feet is one of the earliest symptoms. If so, your patient, on inquiry, will tell you that he feels as if there were a blanket or even a board between his soles and the surface on which he steps. If a quick glance at the pupils shows both smaller or larger than normal, and on turning his face to the light they fail to contract, your suspicion is confirmed; while if, on asking him to be seated and cross his legs, a tap on the great extensor tendon of the knee-joint just below the patella fails to elicit any quick upward jerk of the foot, the so-called "knee-kick," then you may be almost sure of your diagnosis, and proceed to work it out at your leisure. On the other hand, if an elderly gentleman enters with a curiously blank and rather melancholy expression of countenance, holding his cane out stiffly in front of him, and comes toward you at a rapid, toddling gait, throwing his feet forward in quick, short steps, as if, if he failed to do so, he would fall on his face, while at the same time a vibrating tremor carries his head quickly from side to side, you are justified in suspecting that you have to do with a case of _paralysis agitans_, or shaking palsy. Last of all, your physiognomy of disease includes not merely its face, but its voice; not only the picture that it draws, but the sound that it makes. For, when all has been allowed and discounted that the most hardened cynic or pessimistic agnostic can say about speech being given to man to conceal his thoughts, and the hopeless unreliability of human testimony, two-thirds of what your patients tell you about their symptoms will be found to be literally the voice of the disease itself speaking through them. They may tell you much that is chiefly imaginary, but even imagination has got to have some physical basis as a starting-point. They may tell you much that is clearly and ludicrously irrelevant, or untrue, on account of inaccuracy of observation, confusion of cause and effect, or a mental color-blindness produced by the disease itself. But these things can all be brushed aside like the chaff from the wheat if checked up by the picture of the disease in plain sight before you.