A clinicopathologic analysis of 81 cases of giant lymph node hyperplasia was undertaken, with review of previously reported cases. Most of the lesions were intrathoracic. The lesions were discovered most often on routine roentgeno‐grams of the chest or because of pressure symptoms or the presence of a palpable mass if outside the thorax. Evidence is presented that the lesions are enlarged, hyperplastic, altered lymph nodes. They have been divided into 2 histologic types: the hyaline‐vascular lesions, which were most numerous, were characterized by small hyaline‐vascular follicles and interfollicular capillary proliferation; the plasma‐cell lesions were characterized by large follicles with intervening sheets of plasma cells. Systemic manifestations, such as fever, anemia, and hyperglobulinemia, were frequently associated with the plasma‐cell lesions. These clinical signs and other data presented appear to favor an infectious or inflammatory etiology. All the lesions have behaved in a benign fashion, and complete surgical excision has been curative.

The Rye Conference histologic classification of Hodgkin's disease has been applied retrospectively to a series of 176 previously untreated cases of Hodgkin's disease. Three different pathologists independently and unanimously agreed in two‐thirds of the cases on assignment of cases to one of the four categories: lymphocyte predominance, nodular sclerosis, mixed cellularity, and lymphocyte depletion. The classification was found to be effective in predicting prognosis even within clinical staging groups. Nodular sclerosis emerges as the largest histologic group and has a favorable prognosis. The usual manner of spread in Hodgkin's disease was to adjacent lymph node groups. Noncontiguous dissemination, when it occurred, was more than twice as frequent in the mixed cellularity and lymphocyte depletion types, compared to nodular sclerosis. Nodular sclerosis involving lung has shown a favorable prognosis, unlike mixed cellularity. Survival appears to be increased in all histologic categories after intensive wide‐field megavoltage radiotherapy.

Histochemical methods for the demonstration of enzyme activities and carbohydrates were applied to the bladder of the toad, Bufo marinus. The three cell types in the mucosa (ordinary epithelial cell, goblet cell, and mitochondria-rich cell) were found to be distinctive with the methods used. Dehydrogenase enzyme activities were highly concentrated in the mitochondria-rich cells. Membrane-associated ATPase activity was found in the basal cell-membranes of the mucosal cells, where active sodium transport is thought to occur. The potentialities of the various cell types for active electrolyte transport are discussed.There has been considerable interest in the toad bladder in recent years because of its capacity to transport sodium ions and to respond to posterior pituitary hormones in vitro. Numerous physiological studies of these properties have been carried out using this relatively simple cellular membrane. (Leaf et al., '58, '59, '60a, '60b, '61; Leaf, '60; Bentley, '58; Hoshiko and Ussing, '60; Rasmussen et al., '60; Crabbe, '60; Frazier et al., '62; Frazier, '62; Orloff and Handler, '61.) The mucosa has been shown to be the active portion (Frazier, '62; Frazier and Leaf, '63), and in many of these studies it has been assumed for purposes of interpretation that it is made up of a single, uniform population of cells. However, it has been known to morphologists since the last century that three types of cells exist in the mucosa (Schiefferdecker, 1884;List, 1887), and recent electron microscopical studies have confirmed and extended the earlier histological observations. (Peachey and Rasmussen, '61; Choi, '63; Carasso et al., '62; Keller, '60a.) The mucosa has been shown to be a sheet of cells, made up largely of epithelial cells without special cytological differentiation, the "ordinary epithelial cells," but also containing goblet cells, and cells with an unusually high concentration of mitochondria, the "mitochondria-rich cells."The purpose of this investigation was to assess with histochemical methods the metabolic potentialities and the possible interrelationships of the different cell types in the bladder mucosa. MATERIALS AND METHODSStudies were carried out from August through May on mature female Bufo marinus, kept in moist earth and fed twice weekly on meal-worms. The animals were pithed and the bladders were Femoved, rinsed in frog Ringer's solution (Leaf et al., ' 5 8 ) , and agitated gently with air bubbles 5 to 30 minutes to allow the bladder to contract. This resulted in a thickening of the epithelium and permitted better staining and clearer definition of structure with the light ~nicroscope.~ The bladders were drained and either fixed (see below) or quick-frozen in isopentane at dry-ice temperatures, and sectioned at 10 w in a cryostat at 18°F. Frozen sections were mounted on coverslips and airdried 5 to 30 minutes before incubation. Dehydrogenase methodsThe cryostat sections were incubated at 37°C in substrate solutions prepared fresh daily, after which they were placed directly int...