IT HAS OFTEN been discussed whether rheumatoid arthritis (RA) is a disease sui generis and whether there is any symptom or lesion specific to it. In a far-advanced stage, RA often has so characteristic a complex of symptoms as to be diagnosable at a glance. Especially typical are the changes in the metacarpophalangeal joints, with crookedness and ulnar deviation of the fingers. The symmetry of the articular lesions makes the ailment all the more recognizable in a fully developed stage. This gives the impression of a specific disease merely from a physical examination; atypical cases are by no means uncommon, however. I have had great difficulty in making an early diagnosis in some cases, the early symptoms of which resembled flatfoot or unilateral affection of the knee joint. In such cases it has usually been the sheepcell test which has clarified the situation. Granulomas in Collagen Diseases Various laboratory