Another more objectionable, dangerous, and less voluntary motion is the sudden jerking of the head upward, or to one side when excited under the saddle or in harness. The disorderly movements are not, as a rule, seen while the animal is at rest, but seem to be produced under the stimulus of exertion. They appear to be quite involuntary, and suggest the dread caused by the settling or buzzing of an insect about the nose or ears, but occur in the depth of winter in the absence of insect life, as well as in midsummer. The suddenness and involuntary nature of the movement is suggestive of epilepsy, but there is no indication of attendant unconsciousness. From choreic movements it is apparently distinguished, by its presence only when ridden or driven. It is unquestionably associated with hypersensitiveness of the nerve centres, and yet in many cases it appears to be a reflex originating in a specially tender or sensitive part of the skin or mucous membrane. In more than one instance in this college clinic the trouble was corrected by the section of both facial branches of the 5^{th} cranial nerves as they emerged from the infra-orbital foramina. Abnormal Movements of the Tongue. Some horses double the tongue downward, others upward of the bit; others protrude the tongue and give it a sinuous, serpentine motion which causes alternate protrusion and retraction. Flapping of the Lower Lip. This habit of rapid opening and closing of the lower lip so as to produce a disagreeable flapping noise by striking it against the upper, is seen in many horses and proves a most objectionable trait in harness or saddle animals. Rhythmical Movements of the Nose. Certain horses apply the protractile end of the nose against the lower lip and spend hours in succession in moving it rhythmically forward and backward, or from side to side. Weaving. Movement like a Bear in a Cage. This consists in a lateral rocking of the head and neck, and sometimes of the chest as well with alternate stepping on the right and left fore feet. It has been supposed to represent the movement of the weaver in working a hand loom, or still better the movement of a caged wild beast in constant turning toward the right and left of the front of his cage. The motions are as regular as a pendulum, and involve the contraction of corresponding groups of muscles on the two sides of the body. They seem, in some cases, to begin in impatience in waiting for the feed, while other horses in the same row are being attended to first, but when the habit has been formed it may be continued most of the time in the intervals between feeds as well. Nervous horses and those that are hearty feeders are the most subject to this infirmity. Disorderly Movements of the Limbs.