Morphological gradients in the starling basilar papilla

The starling cochlea was studied with TEM at four locations along the basilar papilla to investigate gradients in morphological features over the papilla's length and width. Hair cell shape changes continuously from neural to abneural and from basal to apical. Unlike the situation in mammals, there are no distinct populations of hair cells; the previously described types (tall hair cells and short hair cells) are merely extremes in a continuum. Contacts between THC are a normal feature. Except at the base of the papilla, SHC have very large cuticular plates, suggesting a micromechanical function for these cells. In contrast to the THC, the SHC normally completely lack afferent innervation; this indicates that their function is restricted to within the basilar papilla itself. © 1992 Wiley-Liss, Inc.     

Faba Bean Necrotic Yellows Virus Naturally Infects Phaseolus Bean and Cowpea in the Coastal Area of Syria

In an attempt to identify possible summer hosts of the faba bean necrotic yellows virus (FBNYV), a field survey was conducted in the coastal area of Syria. Using a monoclonal antibody to FBNYV in indirect ELISA, FBNYV was detected in a large number of samples from Phaseolus vulgaris L. and in a few samples from Vigna unguiculata (L.) Walp. in which it caused severe symptoms. This is the first report of natural infection of P. vulgaris and V. unguiculata with FBNYV.     

Zell- und stoffwechselphysiologische Untersuchungen an der Wurzel von Lemna minor L. unter besonderer Berücksichtigung von Kalium- und Kalziummangel

Ohne ZusammenfassungMit 12 Textabbildungen.Im Auszug vorgetragen auf der Botanikertagung Kassel 1949.     

The milky spots on the chest wall in newborns

The histologic properties of pleural adipose organs were studied in 14 newborns. These organs contain milky spots, in which lymphocytes, macrophages and plurivacuolated fat cells are present. The milky spots have a mesothelial covering, persist to the age of 9 months and seem to act as defence devices and a site of fluid exchange.     

Über den Formenkreis desCirsium Sintenisii Freyn

Ohne Zusammenfassung     

Effects of antioxidants and haemoglobin status on the t-butyl hydroperoxide-induced oxygen uptake by red blood cells

Oxygen uptake by erythrocytes exposed to t-butyl hydroperoxide (t-BHP) exhibited an induction period. The rate of oxygen consumption can be reduced by antioxidants and blood plasma. The induction time was not appreciably modified by the antioxidants tested, however, plasma increased it by a factor of two. The in vivo pretreatment with diethyl maleate (0.6 g kg-1) produced increased rates of oxygen uptake without changes in the induction period, while vitamin E (12.5 mg kg-1) elicited lower oxygen consumption rates and longer induction times, compared to those observed in cells from control rats upon addition of the hydroperoxide. These results suggest that the antioxidants tested on the t-BHP lipid peroxidation in erythrocyte suspensions act as inhibitors and/or retarders of the process. Furthermore, lipid peroxidation induced in these conditions seems to depend upon the haemoglobin status of the cells as oxygen uptake, malondialdehyde production and chemiluminescence were significantly higher in methaemoglobin-containing cells than in those containing oxyhaemoglobin.     

Preserved life positions of some Jurassic bivalves

The observed life positions of 23 species of Jurassic bivalves are recorded and compared to reconstructions derived from functional interpretations of their morphology and comparisons with Recent relatives. In the majority of cases, these inferences correspond with field observations. There are, however, cases such ashognomon where likely reconstructions differ. These could easily lead to an erroneous interpretation of the autecology of some species.     

The sweet jelly of Combretum lanceolatum flowers (Combretaceae): a cornucopia resource for bird pollinators in the Pantanal, western Brazil

 The pollination biology of the neotropical scandent shrub Combretum lanceolatum was studied in the seasonally-flooded Pantanal region in western Brazil. This plant bears horizontally oriented inflorescences, whose yellowish green flowers begin to expand at dusk and are fully open at dawn. Instead of fluid nectar the flowers produce sweet gelatinous secretion in form of pellets. The glandular complex of the flower is composed of the inner wall of the receptacle and its tubular extension, being equivalent to the nectariferous disk of the nectar-producing species within the genus. The jelly is produced at night, contains mannan and is imbibed by free hexoses. It originates by swelling and disintegration of the inner wall, after contact with the nectar generated concomitantly in the mesophyll. Combretum lanceolatum is unique within the genus in its production of jelly pellets instead of liquid nectar. A new term, the jelly-flower, is proposed for flowers with this kind of reward. The pellet is not replaced once removed by a bird, and thus resembles a fruit in its availability to consumers, another unique feature that distinguishes this species within the genus. The jelly pellets offered by the many flowered branches attract a great diversity of bird visitors (28 species from eight families), which feed on this copious food resource and pollinate the flowers. The most effective pollinators probably are thrushes, tanagers, and orioles. Flocking parakeets and macaws sometimes feed on the petals, thus acting as flower plunderers. Combretum lanceolatum presents a high fruit set under natural conditions, which likely favours its spreading and becoming a weed species. Received July 11, 2000 Accepted November 18, 2000