PINUS BUCHANANII,A NEW SPECIES BASED ON A PETRIFIED CONE FROM THE OLIGOCENE OF WASHINGTON

A silicified seed cone of Oligocene age from the Olympic Peninsula of Washington represents a new species of Pinus. The cone was about 8 cm long and 3 cm at its widest diameter in the living condition. Its scale apices are thickened and each has a dorsal umbo. Internal cone construction confirms the assignment of the new species to Pinus and suggests affinity with the subsections Australes and Ponderosae of the section Pinus, subgenus Pinus. The cone is peculiar in having a stout bract trace that is slightly concave on its adaxial side and in having resin canals that diverge from the axial secretory system toward the bract but constrict markedly and terminate before entering the bract.     

The needle necropsy.

The technique of limited necropsy by histological examination of needle tissue cores obtained percutaneously is indicated when a full necropsy is not justified owing to the risk of infection or when tissue for special investigations is needed soon after death without recourse to full necropsy facilities. The method is ideal for detecting conditions producing diffuse changes in an organ. Because the cadaver is preserved essentially intact relatives who refuse permission for a standard necropsy might consent to a needle necropsy if this option is offered to them.     

Analysis of cell movements and fate mapping during early embryogenesis in Drosophila melanogaster

Four spatially differentiated surface regions, called aeropyle crown, flat, stripe, and micropyle, are found on the mature eggshell (chorion). Specializations of the apical surfaces of the secretory follicular epithelial cells are implicated in the formation of regional patterns on the chorion. Some of these specializations are restricted to cells overlying certain regions; others are shared by more than one region. Differences between regions are more apparent on the surface than within the bulk of the chorion. Evidence is presented that distinct cell populations, corresponding to the regions, are present long before the start of choriogenesis. One hundred eighty-six chorion-specific polypeptides have been resolved by two-dimensional gel electrophoresis. Fifteen of these are found entirely or predominantly in the aeropyle crown and stripe regions, while eight others are restricted to the aeropyle crown region. Certain of the spatially restricted components are quite unusual in their amino acid compositions when compared with previously analyzed chorion components. Others are closely related, although clearly distinct.