Differentiating Type i and Type ii Alveolar Cells in Rat Lung by OsO4NaI Staining

The fixing-staining mixture consisted of 1 part of 2% aqueous OsO₄ and 3 parts of 3% Nal in distilled water. Fresh lungs were cut into 2 mm slices and immersed in this solution for 24 hr at room temperature. Controls were fixed in buffered OsO₄ alone. Selective staining of type II alveolar cells was shown by the OsO_t-NaI mixture but was absent in the controls. No additional staining of the sections was required, and the selectivity was readily observable in either paraffin or Araldite sections by light microscopy and in Araldite sections by electron microscopy     

Saurian Malarial Parasites in Eastern Panama

SYNOPSIS Plasmodium gonatodi sp. nov. is described from Gonatodes albogularis fuscus of eastern Panama. It is characterized by elongate gametocytes and polymorphic schizonts containing 12-46 nuclei when apparently mature. Both proerythrocytes and erythrocytes are commonly parasitized, host cells are hypertrophied and distorted, and their nuclei are displaced. Prematuration sexual stages may be irregularly shaped and larger than mature gametocytes.
Plasmodium diploglossi Aragão and Neiva , 1909 is reported from Mabuya mabouya in eastern Panama, and Plasmodium morulum sp. nov. is described from this host. P. morulum usually parasitizes immature erythrocytes, and is characterized by lenticular or oval to round gametocytes, and schizonts with 14-40 nuclei usually arranged in a globular mass. Host cells are slightly hypertrophied and distorted, and their nuclei are usually displaced. Inoculation of infected blood into clean hosts produces numerous schizonts in white cells as well as in the erythrocyte series.
Pigment in both P. gonatodi and P. morulum , if present, consists of a few minute dark dots which do not meet the polarized light test for hemozoin.     

THE FINE STRUCTURE OF BRUNNER''S GLANDS IN THE MOUSE

Examined with the electron microscope, the secretory cells of the submucosal glands of Brunner in the mouse present a curious combination of the fine-structural features of both serous and mucus-secreting cells. The cells have numerous mitochondria, abundant basal ergastoplasm, dense secretory granules that bear a superficial resemblance to pancreatic zymogen granules, and an unusually extensive Golgi apparatus. The prominence of the lamellar, vesicular, and vacuolar elements of the Golgi complex facilitates detailed observation of these components. More evident than in other glandular cells, aggregates of small vesicles appear to represent the transitional elements and are vehicles for transport of the product between the ergastoplasm and the Golgi complex. The numerous vesicular evaginations of smooth-surfaced regions on cisternae of the rough-surfaced endoplasmic reticulum and accumulations of innumerable vesicles of similar size in the area between the nearest profiles of the ergastoplasm and the Golgi complex support this contention. The cytological characteristics and physiologic properties of Brunner's glands in various species are discussed briefly. It is concluded that the submucosal glands of the mouse are excellent material for exploration of the ultrastructural correlates of both protein and carbohydrate secretion, and it is suggested that their secretion may have functions other than those generally attributed to them, namely, chemical and mechanical protection of the duodenal surface epithelium.