The gliding reptiles of the Upper Permian

The skeleton of a long-ribbed reptile from the Upper Permian Marl Slate of north-east England is described. The animal is assigned to the genus Weigeltisaurus , previously recorded from the Kupferschiefer of West Germany. Long-ribbed reptiles from the Upper Permian of Madagascar are also considered. Daedalosaurus Carroll, 1978 is a junior synonym of Coelurosauravus Piveteau, 1926. The European and Madagascan genera can be accommodated within a single family Coelurosauravidae, Infraclass Eosuchia. The skull is diapsid with an incomplete lower temporal arcade. Comparison with the modern Draco and the Upper Triassic kuehneosaurids supports the conclusion that the coelurosauravids were effective gliders.     

Nemerteans of the Great Barrier Reef 4. Anopla Heteronemertea (Valenciniidae)

A new valenciniid heteronemertean, Valencinina albula , gen. et sp. nov. from the Great Barrier Reef province of Australia, is described and illustrated. This is the first record of a valenciniid from Australasian waters.     

The middle ear of the skull of birds: the ostrich, Struthio camelus L.

The morphology of the middle ear region including die basicranium and quadrate of Strulhxo is very simil.n to ilic same region in the orders Procellariiformes, Pelecaniformes, Ciconiiformes and Sphenisciformes. Struthio though, has some unique middle ear characters such as die lack of a chorda tympani nerve, the arrangement of die glossopharyngeal and vagus nerve foramina, die structure in the upper neck of die external ophthalmic vein and die position of die Eustachian tube. The articulatory surfaces for the quadrate bom on die zygomatic process of the squamosal and the mandible are unique in Struthio when compared to the several orders mentioned above.     

Morphology of the hypothalamus in advanced teleost fishes

A remarkable structure in the hypothalamus of brachiopterygian and actinopterygian fishes consists of the inferior lobes, nucleus rotundus and torus lateralis. Optic connections are predominant among a variety of fibre paths.  

ZUSAMM ENFASSUNG

Actinopterygier (und Brachiopterygier) besitzen im Hypothalamus eine spezielle, oft beachtlich ausgeprägte Region; diese besteht aus den Lobi inferiores, dem Nucleus rotundus hypothalami und dem Torus lateralis. Unter den reichhaltigen Faserverbindungen haben die meisten optischen Charakter.     

Der Knotenbau einigerRubiaceae

The leaf base vascularization in most of theRubiaceae corresponds to the unilacunar pattern with one complex trace. Only some species are known to have a trilacunar nodal pattern with three traces. In the unilacunar type one pair of smaller bundles separates from the complex lacunary leaf trace laterally, each soon forking into two arms: One arm becomes a marginal vein of the petiole, the other, besides supplying the stipules, forms a ± distinct vascular bridge within the cortex of the nodal flanks. In theRubieae this flank bridge develops as a very distinct vascular ring commissure out of which the whorled leaf-like appendages are vascularized; only the opposite true leaves receive their complex trace out of the lacunes directly. Axillary branches originate only from these true leaves.

     

Ultrastructure of the stylar canal cells ofCitrus limon (Rutaceae)

The ultrastructure of the canal cells and the canal filling substance ofCitrus limon have been studied. At maturity the canal cells are very rich in cytoplasm. Their inner tangential walls lining the canal are much thickened and formed by two layers: the outer corresponds to the original wall, the inner is formed by subsequent deposition of abundant materials of different origin. This thickening occurs at the same time as the filling of the stylar canal. Both events are paralleled by considerable dictyosomic activity, the formation of a large amount of rough endoplasmic reticulum, and the incorporation of small cytoplasmic masses into the cell wall, due to plasmalemma evaginations. — The material in the stylar canal has a heterogeneous ultrastructure aspect and consists of polysaccharides, proteins and lipids; it presumably provides nutrients for the growing pollen tubes.Research performed under CNR program Biology of Reproduction.     

Anatomy and evolution in MacaronesianEchium (Boraginaceae)

The endemic Macaronesian members of the genusEchium (Boraginaceae) were examined anatomically to elucidate their relationships. Vessel length to breadth ratio was used as the initial guide to the relative primitive or derived nature of each taxon. Together with other features (e.g. trichome structure) it was possible to establish the phylogenetic pathways within this recently evolved relict group (Fig. 1).     

BCG-induced chronic pulmonary inflammation and splenomegaly in mice: suppression of PHA-induced proliferation, delayed hypersensitivity to sheep erythrocytes, and chronic pulmonary inflammation by soluble factors from adherent spleen cells

C57BL/6 (B6), but not CBA, mice develop intense chronic granulomatous inflammation (CGI) in the lungs and spleen in response to an iv injection with killed BCG in an oil-in-saline emulsion (BCG-E). Concomitant with the development of CGI, these mice show diminished responsiveness to PHA and LPS, as well as suppression of antibody synthesis and production of delayed hypersensitivity (DH) to sheep erythrocytes (SRBC). Suppression results from the development of adherent, Thy-1^?, Ig^? spleen cells. The present study shows that cells from inflamed spleens of BCG-E-treated B6 mice elaborate factors in vitro which (a) inhibit PHA-induced proliferation of both normal syngeneic and allogencic cells, (b) suppress DH to SRBC in B6 mice, and (c) diminish the intensity of BCG-E-induced CGI in the lungs and spleens of B6 mice. These factors are produced by adherent Thy-1^? cells in BCG-injected mice but not in similarly treated CBA mice. These factors may be important in understanding the control of immunologically mediated chronic inflammation.     

Entwicklungstendenzen im Fruchtbau der anemochoren Boraginaceengattungen Mattiastrum und Paracaryum

Fruchtanatomische Untersuchungen von 13 Mattiastrum- und sechs Paracaryum-Arten (Boraginaceae) zeigen, daß der Perikarpbau weitgehend gattungsspezifisch ist. Die geflügelten Klausen unterscheiden sich in Flügelaufbau und -ausbildung. Alle Paracaryum-Arten besitzen einen großen Flügelhohlraum und nur auf der Flügelaußenseite das typische Cynoglosseae-Exokarp, dazu ist die Testaepidermis durchweg großzellig. Die Endokarpsteinzellen können besonders bei Mattiastrum und Paracaryum Sect. Paracaryum auf der Adaxialseite palisadenartig ausgebildet sein. Bei einigen Mattiastrum-Arten wird eine Achänenbildung diskutiert.     

Photosynthesis in leaves of the juvenile and adult phase of ivy (Hedera helix)

Abstract Photosynthetic and anatomical parameters of leaves from the juvenile and adult part of an ivy plant (Hedera helix L.) have been determined and compared with each other. Light-saturated net photosynthesis (per unit leaf area) was about 1.5 times higher in adult leaves than in juvenile ones. The lower photosynthetic capacity of juvenile leaves was caused by a lower stomatal and especially a lower residual conductance to the CO₂-transfer. This corresponds with anatomical features of the leaves, i.e. lower stomatal frequency, fewer chloroplasts per cell, and – most important – thinner leaves, as well as with a less efficient photosynthetic apparatus measured as Hill reaction of isolated broken chloroplasts and activity of ribulose bisphosphate carboxylase. No differences in the respiration in light (relative to net photosynthesis) and in the CO₂-compensation concentration could be detected between the two leaf types. These observed anatomical and photosynthetic parameters of the juvenile and adult ivy leaves resemble those reported for shade and sun leaves, respectively, although the leaves investigated originated from the same light environment.