this as in the last example nævi were present. In an unpublished case of the author’s the hypertrophied hand was much stronger than its fellow; but in the example[37] already quoted there was no evidence of increased development of muscle. In two instances of unilateral hypertrophy of the face described by Friedrich[38] and Passauer,[39] the increased growth involved the whole of the parts of the affected side, even to the teeth and tongue, and in Friedrich’s patient, and in a case brought by Dr. Heumann before a Medical Congress in Darmstadt, the hair was more developed, and the secretion of saliva was excessive on the affected side, but the muscular power and arterial supply were not specially referred to. In a case of Eve’s the facial hypertrophy extended to the brain. In the ordinary forms of congenital hypertrophy the size of the part is augmented by an unequally distributed hyperplasia of the skeleton and soft parts. Almost all the cases narrated in detail are of this kind. In nearly all, the arterial supply is proportionate only to the normal size of the part, and the functional capacity (power, sensibility, &c.), although not seriously altered, is to some extent deteriorated. The cases may be for practical purposes divided into two groups: 1. Without deformity, the enlarged segment preserving the normal contour in other respects. 2. With deformity. _a._ From predominant development of the adipose or vascular tissues. _b._ From secondary articular distortions. _c._ From associated defects of development, as syndactyly, &c. The condition of the different elements of the enlarged part is as follows: The _bones_ are always enlarged. Their general shape is commonly preserved, but occasionally their extremities are deformed by outgrowths at the line of junction with the articular cartilage. The hypertrophy reaches its greatest proportionate extent in the digits, while increase in size of the bones of the forearm, arm, leg, and thigh, is, as a rule, only demonstrable during life by admeasurement of length. No histological abnormality has been detected in the osseous tissue, but Eve (_l.c._) found the cancellous tissue of the enlarged bone soft and the medulla fatty. The _articular surfaces_ may present no peculiar features, but in some cases the cartilages show irregularities of surface. The ligaments are usually greatly thickened. The synovial membrane commonly has the ordinary characters, varied only by an excessive development of the plicæ adiposæ. The range of motion is sometimes normal; in other cases the voluntary movements are more or less diminished in extent, while a fair amount of passive mobility is preserved; and in others there is complete ankylosis. Distortions, such as lateral deviation and hyper-extension, are frequent. The former appears to depend upon malformation of bone.