The role of vegetative and reproductive attributes in the classification of the Orchidaceae

Ninety-three orchid taxa have been arranged into three classificatory dendrograms employing respectively 40 reproductive, 34 vegetative and 74 attributes combined, and forming the hierarchy by means of group-average clustering. According to these results the non-specificity hypothesis does not hold well for vegetative versus reproductive attributes. Both types of attributes are equally efficient predictors of the classification based upon the total data, though neither data set is a very reliable predictor. Hence both should be employed in the production of general classifications and when considering the phylogenetic relationships amongst orchids.     

Movement of Ions and Electrogenesis in Microorganisms

The relationship between movement of ions and the electricalproperties of microorganisms (algae, fungi, and bacteria) arereviewed, with particular emphasis on the giant alga, Nitella,and the fungus, Neurospora. The hypothesis is presented thatthere are two basically different components to the membranepotential of both organisms: (1) one arising from the diffusionof sodium, potassium, and hydrogen ions down their chemicalgradients, and (2) one associated with the utilization of energyand the active efflux of hydrogen ions, and attributed to an"electrogenic H⁺ pump." Numerous discrepancies between the measuredelectrical properties of the algae or fungi and the predictionsof ordinary ion-diffusion theory can be accounted for by suchan H⁺ pump, and its existence is further supported by a fewindirect experiments on the bacteria.     

Fungicidal activity and chemical constitution

Six 4-(1-phenylalkyl)-, eight 4-(1-cyclohexylalkyl)-, seven 4-(1-cyclo-pentylalkyl)- and seven 4-(1-cyclobutylalkyl)-2,6-dinitrophenols, together with some derivatives, were tested against the powdery mildews of apple (caused by Podosphaera leucotricha) and blackcurrant (caused by Sphaerotheca mors-uvae) in the greenhouse and in field trials, against rose mildew (caused by S. pannosa) in the field, and against Venturia inaequalis in spore germination tests. Highest activity in the greenhouse was shown by members of the cyclobutyl series with 4–6 carbon atoms in the alkyl group. No phytotoxicity on healthy foliage occurred with any compound in these series.     

Polyphagy,flightlessness, and reproductive output of females: a case study with bagworms (Lepidoptera: Psychidae)

Abstract 1. We evaluated the relation between plant‐mediated larval traits and the fitness of female bagworms, Thyridopteryx ephemeraeformis Haworth (Lepidoptera: Psychidae) by sampling 29 populations of bagworms on five plant genera (Thuja, Pinus, Picea, Juniperus, and Gleditsia). 2. Compared with those on other genera of plants, female larvae on Thuja attained a larger size at pupation and developed faster. The superior quality of Thuja as a larval food plant resulted in a higher potential fitness of females, as indicated by a low level of pupal mortality and high fecundity. 3. The fecundity of females increased with pupal size on different plant genera, and the effect of host plant genus was negligible compared with pupal size. 4. The mating success of females varied among different populations (0–37% unmated females), but neither host plant, emergence time, nor the size of females had a significant influence on the proportion of mated females. 5. The conversion of adult biomass into reproductive tissue, measured as the ratio between the biomass of eggs divided by the biomass of calling females, increased with the pupal size of females and approached 90% for large females. The high rate of egg conversion in bagworms may be related to the neoteny of short‐lived females that invest little in somatic tissue.     

Characterization of Chemical Contamination in Shallow-Water Estuarine Habitats of an Industrialized River. Part 1: Organic Compounds

The lower six miles of the tidal portion of the Passaic River (Study Area) has been heavily industrialized since the mid-1800s. The objectives of this study were to: quantify the present extent and magnitude of chemical contamination in surface sediments from the Study Area; evaluate the contamination in the Study Area relative to a reference area and surrounding regional waterways; assess the potential for adverse effects to aquatic organisms; and identify spatial gradients in concentrations that may indicate potential point-sources of chemicals. Because existing ecological communities center primarily on intertidal mudflats in the Study Area, composite surface sediment was collected from 15 mudflats to generate a realistic assessment of fish and wildlife exposure to sediment contaminants. This study showed that present concentrations of organic contaminants are elevated throughout the Study Area and are generally higher than concentrations in the reference area and regional waterways. A screening-level analysis showed that there is potential for adverse effects to sediment-associated organisms from a number of chemicals. No spatial trends were apparent for most compounds evaluated, consistent with the presence of multiple sources of chemicals in the Study Area. The exception is semivolatile compounds, which appear to be localized to specific mudflats, indicating potential point-sources of contamination for these chemicals.     

Thermoregulation in the Red-beillied Blacksnake, Pseudechis porphyriacus (Elapidae)

Cold Pseudechis porphyriacus aid heating by basking, flattening and tilting. When body temperatures are higher, thermoregulation is achieved by shuttling between sun and shade. A warm snake in a cooling environment frequently coils.
The major factors associated with rate of temperature change in the body core were (1) horizontal gradient between body and neck, (2) posture and (3) vertical gradients from body core to body surface.
The role of behavioral, physiological and physical factors in thermoregulation are discussed.     

Partitioning of 14C-Assimilate Between Sources and Sinks in the Monopodial Orchid Aranda Tay Swee Eng

Aranda Tay Swee Eng, an orchid hybrid with monopodial growthhabit, has a highly integrated source-sink assimilate partitioningpattern. The current inflorescence receives assimilate frommany rather than a few leaves, the vegetative apical shoot competeswith the inflorescence for assimilate supply in the upper shoot,and the fully-expanded leaves themselves constitute a majorsink for assimilate. Implications of these findings for improvementof harvestable yield in monopodial orchids are discussed. Aranda Tay Swee Eng, monopodial orchids, assimilate partitioning, source-sink relationships     

Simuliidae (Diptera) of Sabah (British North Borneo)

This paper is based on collections made in Sabah by John Smart and on an examination of named material (types) in the British Museum (Natural History), London.
Segregates discussed comprise:(1) six new species, (2) five named species from the area, described by the late F. W. Edwards (1933).