The radiating fascia, and perhaps even the tendon of the palmaris longus, are made tense and prominent by the shrinking of the new material, but the palmaris longus has no primary share in the production of the deformity, and in fact the disease may be present where the muscle is undeveloped. Repeated experience in operations has proved that the flexor tendons are not affected, and that even in long-standing cases the joints may be fully extended immediately after the division of the morbid fibrous bands. It may be accepted as a principle that the development of a tendon once completed, the tissue has little or no disposition to retrograde changes in the direction of its length. When the most prominent parts of the contracted cords are exposed for excision they bear much resemblance to tendon in contour and striation, but they are less bluish and lustrous in aspect. On dissecting them away from the radiating fascia the transverse fibres interlocking the digital segments of the latter may often be seen unchanged, and in one case in which the disease had attacked the sole the new fibrous tissue could easily be detached from the fascial fibres, which retained all their lustre. The histological appearances of the new growth are those of fibrous tissue. If the disease is spreading, the fibrous strands are intermingled with nuclear proliferation, which extends especially along the course of the vessels. _Pathology._—The study of the character and relations of the diseased structure indicates that it is an inflammatory hyperplasia commencing in the skin and subcutaneous tissue of the palm, involving the fascia secondarily, and replacing the adipose connective tissue which normally serves as an elastic cushion for the palmar surface of the hand and fingers. It must now be considered what is the cause of the morbid process. The view of Dupuytren has already been referred to. He believed that the affection was provoked by repeated injuries of the palmar fascia by pressure and friction from implements used habitually in different mechanical callings; but the facts I have adduced in the discussion of the etiology conflict strongly with the hypothesis. It has been shown that in artisans both hands may be equally affected where only one is brought in contact with the tool, that aggravated forms of contractions may appear in persons who are not at all exposed to any such habitual source of irritation, and, moreover, that the disease appears to be of less than average frequency in certain employments in which the palms are subject to an unusual degree of friction.