Ultrastructural observations on the development of male gametes in Allostoma sp. (Plathelminthes,Prolecithophora)

In the prosobranch snail Littorina littorea (L., 1758) the ultrastructure of the prostate gland cells (pgc) in males and the altered glandular epithelium of the pallial oviduct of females in intersex stage 3 is compared. Regarding form, structure, organelles and secretory products the pgc in males are identical with the corresponding gland cells of the females. Consequently these results demonstrate that in females of intersex stage 3 the epithelium of the pallial oviduct, which originally consists of several (3) glandular parts, is transformed into a male prostate gland.     

Experimental transmission of a sarcosporidian from Alpine ibex to domestic sheep and goats

Sporocysts of Sarcocystis sp. from dogs fed with ibex meat were orally inoculated into kids and lambs. Three kids, given 4 x 10(6) and 4 x 10(4) sporocysts, respectively, died from acute sarcocystosis. Schizonts, though found in all the tissues of these kids, were particularly numerous in the kidneys, brain and spinal cord. Another three kids inoculated with 5 x 10(3) sporocysts and two lambs, inoculated with 1 x 10(6) and 5 x 10(3) sporocysts, respectively, showed no clinical signs and were sacrificed between 111 and 130 days after infection. Mature sarcocysts were found both in the heart and striated muscles of these animals. No parasitic stage was found in two kids and two lambs used as uninoculated controls. Biological differences between Sarcocystis sp. from ibex and the other sarcosporidians with a canine-caprine or canine-ovine cycle are stressed.     

The ultrastructure of the sense organs of some turbellaria rhabdocoela. I. The eyes of Polycystis naegelii Kölliker (Eukalyptorhynchia Polycystididae)

Summary Each pigment-cup eye of Polycystis naegelii consists of two retinal clubs and a single pigmented cell. The latter is divided into two cavities by a septum. Under bright illumination the photoreceptor process appears as a disk containing membranous laminar whorls; under faint illumination the latter are replaced by numerous straight, closely packed, microvilli. This morphological variation is correlated with the intensity of the photoreceptor's exposure to light. The lenticular structures described by previous light microscopists have not been observed.This work was supported by a grant from the Italian National Research Council (C.N.R.)     

The structures of bis(1H,5H-S-methylisothiocarbonohydrazidium) di-μ-chloro-octachlorodibismuthate(III) tetrahydrate and tris(1H-S-methylisothiocarbonohydrazidium) esachlorobismuthate(III)

The structures of bis(1H⁺,5H⁺-S-methylisothiocarbonohydrazidium) di-μ-chlorooctachlorodibismuthate(III) tetrahydrate: (C₂H₁₀N₄S)₂(Bi₂Cl₁₀)· 4H₂O (compound [I]) and of tris(1H⁺-S-methylisothiocarbonohydrazidium) esachlorobismuthate(III): (C₂H₉N₄S)₃(BiCl_5.67I_0.33) (compound [II]) were determined from single crystal X-ray diffractometer data. Both compounds crystallize as triclinic (P ); crystals [I] with Z = 1 formula unit in a cell of constants: A = 10.621(3), B = 9.989(5), C = 7.439(3) Å, α = 88.31(2), β = 84.51(2), γ = 68.88(2)°, final R = 0.0427 for 2229 unique reflections with I 2σ(I); crystals [II] with Z = 2 and cell dimensions: A = 14.109(4), B = 12.209(9), C = 8.206(7) Å, α = 103.54(3), β = 104.95(2), γ = 81.96(2)°, final R = 0.0411 for 3637 unique reflections (1 2σ(I)). The structure of [I] is built up of diprotonated organic cations, water molecules and dinuclear centrosymmetric [Bi₂Cl₁₀]⁴⁻ anions held together by N-HCl, N-HO, O-HCl hydrogen bonds and Van der Waals interactions. The [Bi₂Cl₁₀]⁴⁻ complex consists of two edge-sharing octahedra in which three pairs of bonds of similar length are observed (Bi-Cl_av = 2.602(5), 2.712(4), 2.855(5) Å). The structure of [II] consists of monoprotonated cations and [BiCl_5.67I_0.33]³⁻ anions held together by a tridimensional network of hydrogen bonds. Each bismuth atom is octahedrally surrounded by six chlorine atoms, one of which is statistically substituted by a iodine atom.     

Mégalithes et sociétés préhistoriques : concepts et terminologie

The restitution of the megalith’s technical manufacture, whith their assemblies lines and their sequences, enlarges the coast of the sens incluse in each Corsican monoliths. From the megalithics sites of Poghjaredda of Monte Rotondu (Sotta), Ciutulaghja (Appietu), and Presa (Altaghjè), some specifics activities area (pastoralism for example) or activities structured in the space (villages and tombs of middle Neolithic) interest this study. The contributions of many sciences permit to give an economic and social dimension to the choice of megalithics sites. Then, those choices are an aspect of the Neolithic process in Corsica, making part of sculpture and architecture. This study is conclued by a consideration on the actual worked stones’ terminology.