Just at the time of completing this book another case strongly resembling exophthalmic goitre in man was encountered in a Gray wolf (_Canis lupus_). This animal had a history of enlarged neck and enlarging abdomen for about six months. His appetite and discharges remained about normal but weight was lost and activity reduced to a minimum. Attempts at removing the fluid believed to be in the peritoneum, by the use of diuretics, failing and the beast being in such poor shape, he was killed. An enormous adenomatoid goitre, concentric hypertrophy of the heart, passive dilatation of all cervical and thoracic veins, passive congestion of the liver and congestion of the portal area were autopsy diagnoses. It will be noted that no exophthalmos and nervousness were observed during life. Bone disease and atheroma are at times associated with thyroid insufficiency in man. The former, aside from osteogenesis imperfecta of cretinism, occurred only once in a carnivore and once in a marsupial. There is but one case of atheroma among the sixty cases of thyroid disease. The reaction of the avian thyroid in its hyperplasias is somewhat different from that of the mammalian. The delicacy of the septa and the relative paucity of vessels is perhaps the reason that the gross and microscopic pictures differ from those found in mammals. It should be emphasized, however, that while one can perceive a hyperplasia of the gland of both classes when the testes or ovaries are active, there appears less participation of the thyroid in birds in infectious diseases than is the case for mammals. In simple functional hyperplasia the capsular vessels are prominent, but the cross section need show no change. In the continued hyperplasias the organ remains more solid, being less apt to develop cysts; large cysts are occasionally seen, however, and in one case the entire gland was composed of them. Microscopically the differences are largely of degree in that the process is less frank in development, but the essential changes of swollen epithelia and condensed colloid remain the same. ATROPHIES.