Morphologie und Morphogenese des Bodenciliaten Oxytricha granulifera sp.n. (CiIiophora, Oxytrichidae)

Oxytricha granulifera sp.n. differs from other members of the genus by its subpellicular granules and the strongly shortened dorsal kinety 4. The overall pattern of the morphogenetic events is similar to that known from other Oxytrichidae. However, the oral primordium evolves de novo between the left marginal cirral row and the postoral cirri. The six anlagen of the frontoventral cirri are of different origin. Two anlagen of the proter evolve from parental frontal cirri, two from the opisthe, and one includes basal bodies of the proter and opisthe. Two anlagen of the opisthe evolve from the oral primordium, and three primordia originate from the postoral cirri. Frontal cirrus 1 evolves from the paroral membrane in the proter, and from the oral primordium and the anlagen of the frontoventral cirri in the opisthe. The genus Oxytricha can be subdivided into several groups with regard to the origin of its oral primordium and the development of the frontoventral cirri. The morphogenesis of the dorsal kineties in the Hypotrichida is reviewed. Seven different modes of origin are distinguished. We conclude that morphogenetic features cannot be used in the classification of the Hypotrichida at the generic level, because we have too little information to decide whether special morphogenetic features are important at the generic or species level.     

Potassium Involvement in Stomatal Movements of Paphiopedilum

There are conflicting reports about whether guard cells of Paphiopedilumspp. accumulate K during stomatal opening. In this study X-raymicroprobe analysis and histochemical staining for K indicatedthat K accumulated in guard cells in leaves of Paphiopedilumspp. when stomata opened. Additionally, stomatal opening inepidermal strips of P. harrisseanum could only be induced inan MES buffered KC1 medium. Element analysis ofP. harrisseanumepidermis also indicated substantial levels of K, Na and Cawithin the tissue. We conclude that K is involved in the stomatal movements ofPaphiopedilum. Key words: K⁺ transport, Paphiopedilum, Stomatal movements     

Water Movement into and through Tradescantia virginiana (L.) Leaves: I. UPTAKE DURING CONDITIONS OF DYNAMIC EQUILIBRIUM

Water uptake into the ventral epidermis and the other tissuesof excised T. virginiana leaves was measured separately andsimultaneously when the uptake rates were steady. It was foundthat uptake into the ventral epidermis was proportionately greater,compared with uptake into the remainder of a leaf, than wouldbe expected from the ratio of conductances of the two pathways.This result led to the conclusion that not only is the epidermisa pathway for water transport in the transpiration stream butthat it is an important site of evaporation for stomatal transpiration.     

Correlations Between the Unbound Water Content of Guard Cells and Stomatal Aperture in Tradescantia virginiana L.

When the apertures of stomata in an epidermal strip changedthere was found to be a simultaneous change in the unbound watercontent of the tissue. This occurred even when only the guardcells were living. It was concluded that the change in unboundwater occurred in the guard cells, and possibly the guard cellwalls.     

Effects of Odorants on Pigment Aggregation and cAMP in Fish Melanophores

Odor perception within olfactory neuroepithelium and pigment translocation within melanophores both seem to rely on a cAMP-based second messenger system. From studies on cultured frog melanophores, Lerner et al. (Proc. Natl. Acad. Sci. USA 85:261-264, 1988) suggested that some aspect of odor perception may be mediated by a nonspecific mechanism whose signal is transduced by a cAMP-based second messenger system. In the present study, odorants (β-ionone, benzylaldehyde, cineole, cinnamaldehyde, and octanol), which previously have been shown to stimulate formation of cAMP in the olfactory neuroepithelium, were investigated for possible pigment dispersing and cAMP-increasing effects. Pretreatment of fish melanophores with the adenylate cyclase activator forskolin (1 μM) resulted in an approximately 300% increase in cAMP and an almost complete blockage of noradrenaline-induced pigment aggregation. However, none of the tested odorants were able to increase the cAMP level and only cinnaldehyde and β-ionone were found to have any pigment dispersing activity.     

Rapid isolation of anopheline mosquito eye-colour mutants, based on larval colour change

Abstract. A method is presented for the rapid isolation of eye-colour mutants in anopheline mosquitoes based on their inability to undergo a background-stimulated morphological colour change. For application of this method, larval mosquitoes, whose grandfathers had been mutagenized, were reared in black containers and examined with the naked eye en masse during the third or fourth instar. The vast majority of larvae became dark-coloured; however, rare exceptional pale larvae were observed and examined individually microscopically. Approximately half of the pale types examined were eye-colour mutants. By this method, seven sex-linked mutations in the mosquito Anopheles gambiae s.s. were easily isolated. Additional existing anopheline eye-colour mutants in An. gambiae and An. stephensi were tested and were found to be unable to undergo colour change. Several applications of this simple technique are suggested.     

Mate-locating strategies are related to relative body length and wing colour in the speckled wood butterfly Pararge aegeria

1. The mate-locating strategies of Pararge aegeria (L.) males were studied in relation to adult morphology (dorsal wing colour, forewing length, body length and forewing length : body length ratio) and generation.
2. Males locate females either by perching and defending territories, or by patrolling. Individuals were more consistent in their mating strategies than expected by chance.
3. Forewing length : body length ratio was positively correlated with thorax mass : body mass; relatively short-bodied males had relatively heavy thoraxes. Therefore, forewing length : body length ratio was an index of mass allocation.
4. Perching males had higher forewing length : body length ratios and were paler than patrolling males.
5. The higher forewing length : body length ratio was due to the differences in body length and not wing length. Perchers had shorter bodies than patrollers.