9. =Thyroid.= _Weight_ is 30-60 grms. The _dimensions_ of the lateral lobes are: Length 5-7 cm., breadth 3-4 cm., thickness 1.5-2.5 cm. They should be symmetrical. Note variation in _form_, character of _cut-surface_ (normally glassy, granular and yellowish-pink). The colloid is transparent, yellow or brown in color, and rises above the cut-surface. Cysts of varying size are very common, likewise encapsulated adenomata. A firm, yellowish, moderately enlarged thyroid is often seen in cases of pulmonary tuberculosis. Increase of the stroma with hyaline change and calcification is common. The most important pathologic conditions of the thyroid are: _goitre_ (struma diffusa, nodosa, maligna, benigna, parenchymatosa, hyperplastica, adenomatosa, colloides, gelatinosa, cystica, vasculosa, fibrosa, hæmorrhagica, calculosa, ossea, amyloides, inflammatoria, etc.), _inflammation_ (thyreoditis simplex, purulenta, abscess), _neoplasms_ (carcinoma the most common form of malignant tumor, sarcoma not rare, adenoma and cystadenoma very common, combinations of sarcoma and carcinoma have been observed; other forms rare), _granulomata_ (tubercles and gummata are rare), _parasites_ (echinococcus). Especial examination should be made of the thyroid in cretinism, myxœdema, all forms of cachexia of unknown etiology, infantilism, lymphatic constitution, unexplained death, rachitis, chondrodystrophia, acromegaly, giantism, idiocy, etc. In marked constitutional disturbances conditions of athyreosis, thyreoplasia and hyperplasia of the thyroid may play an etiologic rôle. Accessory thyroids are not uncommon in the neck, in the supraclavicular fossæ and behind the sternum. They usually show the structure of fœtal adenomata, but may become cystic or undergo carcinomatous change. 10. =Parathyroids.= These organs are usually four in number, sometimes more, sometimes only one or two. They are usually paired, and are found near the inner posterior borders of the lobes of the thyroid, near the two terminal branches of the inferior thyroid artery. They vary in size from 3-15 mm. in length, 3-4 mm. broad, by 1-2 mm. in thickness. They are normally brown in color, and soft in consistence. It is often difficult to distinguish them from the hæmolymph nodes that are common in this region. The parathyroids should be examined in all cases of tetany, paralysis agitans, acromegaly, epilepsy, infantile atrophy, myotonia and obscure cachexias. Conditions of supposed hypoparathyreosis have been reported. Hypertrophy of the parathyroids has been observed in acromegaly. Adenoma has been described by several writers. Cysts, fatty degeneration, fatty infiltration, colloid degeneration, cloudy swelling and tuberculosis have been reported as occurring.