ACUTE RHEUMATISM 221 



usually spoken of as the micrococcus rhewmaticus. The organism 

 is sometimes spoken of as a diplococcus, but it is best described 

 as a streptococcus growing in short chains ; in the tissues, how- 

 ever, it usually occurs in pairs. It is rather smaller than the 

 streptococcus pyogenes, and although it can be stained by Gram's 

 method, it loses the colour more readily than the streptococcus. 

 In the various media it produces a large amount of acid, and 

 usually clots milk after incubation for two days; on blood agar 

 it alters the haemoglobin to a brownish colour. Its growth on 

 media generally is more luxuriant than that of the strepto- 

 coccus, and it grows well on gelatin at 20 C. Injection 

 of pure cultures in rabbits often produces polyarthritis and 

 synovitis, valvulitis and pericarditis, without any suppurative 

 change lesions which it is stated are not produced by the 

 ordinary streptococci (Beattie). In one or two instances 

 choreiform movements have been observed after injection. The 

 organism is most easily obtained from the substance of inflamed 

 synovial membrane where it is invading the tissues ; a part 

 where there is special congestion should be selected as being 

 most likely to give positive results. It is only occasionally to 

 be obtained from the fluid in joints. It has also been cultivated 

 from the blood in rheumatic fever, from the vegetations on the 

 heart valves, and from other acute lesions ; in many cases, how- 

 ever, cultures from the blood give negative results. Beattie in 

 a recent paper has shown that in rabbits the arthritis produced 

 reproduces the main features of acute or subacute rheumatism 

 in man, namely, the rapidity with which the affection flies from 

 joint to joint, the tendency to relapses, the contributory effects 

 of exposure to cold, and the absence of gross anatomical changes 

 in the joints. Poynton and Paine cultivated the streptococcus 

 from the cerebro-spinal fluid in three cases where chorea was 

 present, and also detected it in the membranes of the brain. 

 They consider that this disease is probably of the nature of a 

 slight meningo-myelitis produced by the organism. The facts 

 already accumulated speak strongly in favour of this organism 

 being causally related to rheumatic fever, though this cannot 

 be considered completely proved. Andrewes finds that the 

 organism has the same cultural characters and fermentative 

 effects as the streptococcus fiecalis, a common inhabitant of the 

 intestine. Even, however, if the two organisms were the same, 

 it might well be jossible that rheumatic fever is due to an 

 infection of the tissues by this variety of streptococcus. The 

 clinical data, in fact, rather point to rheumatic fever being 

 due to an infection by some organism frequently present in the 



