The soft parts in the immediate vicinity of the inflamed joints may be in some cases more or less congested and oedematous, and the tendinous sheaths, and even the bursæ mucosæ, inflamed and distended with inflammatory products like those in the articulations. Charcot,[119] holding the opinion that arthritis deformans is but a chronic variety of articular rheumatism, quotes Gurlt's statement that in acute articular rheumatism "the medullary tissue of the ends of the bones undergoes a great increase of vascularity, with proliferation of its corpuscles," and remarks that Hasse and Kussmaul have also referred to lesions of the bone and periosteum in that disease. But the condition of the osseous parts of the joints in acute articular rheumatism can hardly be said to be known, and it is premature to speak positively respecting it. [Footnote 119: _Clinical Lectures on Acute and Chronic Diseases_, Sydenham Soc., 1881, p. 148.] Finally, in subacute rheumatism the alterations in the synovial membrane, and especially in the cartilages just described, are likely to be more marked than in the acute form. The DIAGNOSIS of acute polyarticular rheumatism is seldom difficult in adults, but when acute rheumatism localizes itself in one joint or occurs in infancy or early childhood, a diagnosis, especially an early one, sometimes cannot be easily established. The considerations by which acute polyarticular rheumatism may be distinguished from acute gout, subacute rheumatoid arthritis, and gonorrhoeal rheumatism will be given in connection with those topics.