This form of arthritis usually appears in an insidious form after abortion, retention of the fœtus, or post-partum metritis. In cases of epizootic abortion infectious rheumatism sometimes assumes an epizootic form, and completes the devastation begun by abortion. Under other and much rarer circumstances it may follow enteritis of adults or attacks of mammitis, etc. The pathogeny of these forms of arthritis is not difficult to understand, for in the greater number of instances they form delayed consequences of local uterine infection. [Illustration: $1] The soluble products secreted by infectious organisms multiplying within the uterus are absorbed by the uterine mucous membrane, causing slow intoxication; and in consequence of the special elective affinity which the toxins show for the articular serous membranes, and in many cases also for the visceral serous membranes, the special characteristics are developed. Under certain circumstances the joint cavity may even become the seat of true microbic infection. =Symptoms.= The appearance of the first symptoms is difficult to identify, for many cows abort, fail to “cleanse,” or become affected with metritis without infectious rheumatism supervening. It is a long-delayed condition, which may be postponed for weeks or even for several months after an abnormal parturition, and to a time when the symptoms of metritis have almost entirely disappeared. The onset is characterised by difficulty in rising, and soon afterwards by lameness, or by the animal failing to place weight on one of the hind limbs. The affected joint, usually one of the articulations of the stifle, appears markedly enlarged, is not appreciably hot to the touch, but reveals a certain amount of painful sensibility on pressure. The periarticular tissues are infiltrated and the synovial sacs slightly distended. [Illustration: $1] [Illustration: $1] After a few days, a week or two at most, the periarticular swelling diminishes, and the condition appears to remain stationary. Appetite is normal or only diminished. The pain continues, and causes progressive wasting and diminution in the yield of milk. If at this time the practitioner makes a careful digital examination of the diseased region, he may find one of two conditions. In the first, the synovial sacs appear distended, fluctuating and in exactly the same condition as in ordinary bog spavin. This is what has been termed the exudative form of infectious arthritis. In the second, the enlarged joint remains very sensitive, the walls of the synovial sac are thickened, fluctuation is either absent or only slightly marked, but induration is very manifest. This constitutes the plastic form. [Illustration: $1]