ELECTRICAL STIMULATION OF HUMAN FUNGIFORM PAPILLAE

The experiment by Békésy (1964) on electricalstimulation of single, human, fungiform papillae was repeated.Békésy's results were confirmed, that each papillagives rise to only one gustatory quality, and that only thequalities of bitter, salty, sour, and sweet are reported. Inaddition, maps of the distribution of the papilla types weremade for two male and two female Ss. Data to support the existenceof quality groupings were found in only one S.     

Honeybees and the nectar of Echium plantagineum L. in southeastern Australia

An account is given of the flower of Echium plantagineum in south-eastern Australia, including stages and timing of flowering, behaviour of raindrops in the flower and aspects of floral microclimate. The concentration of nectar solutes varied with time and site, with means varying from 2 to 62% (as g sucrose/100 g solution). There was a significant negative correlation between nectar solute concentration and ambient relative humidity: the drier the air, the more concentrated the nectar. Rates of nectar secretion per flower varied with the bagging method, with long-term bagging reducing net secretion rates, possibly because of re-absorption. Rates varied with time, day and site, with a temporal pattern of change suggesting a link between rates of photosynthesis and secretion. Maximum nectar secretion rates in short-term bagging experiments were ca. 300 μg sugar/flower/hr (equivalent to > 2 mglflower/24 hr). Secretion rate was correlated with flower density. As flower density increased, secretion rate per flower decreased; rate of sugar production per unit area increased relatively more slowly than flower density. E. plantagineum could produce > 500 mg sugar/m²/day. Honeybees foraged on E. plantagineum only at ambient air temperatures above ca. 17°C unless irradiance exceeded ca. 750 W m^-2. Foragers collected nectar or pollen alone, or both, with the type of visit significantly correlated with nectar solute concentration. Below 35% (as g sucrose/100 g solution) most bees took pollen only; above 40%, most took nectar. Mean standing crop of nectar was generally < 100 μg/flower when most bees were taking nectar, but could exceed 1000 μg/flower when bees were absent or foraging mainly for pollen. Honeybees did not always remove all nectar from flowers they probed. Reabsorption of residual nectar may augment the following day's secretion.     

Hormones, Reproductive Behavior, and Speciation

A research plan is outlined which combines two ordinarily separatelines of investigation, namely, the reciprocal interaction betweenhormones and behavior and the role of behavior in the evolutionand maintenance of species, bringing both to bear on outstandingquestions in behavioral and evolutionary biology. This integrativeapproach to animal behavior, which spans three levelsµphysiology,behavior, and evolutionµshould not only yield answersto specific questions within each level of analysis, but, bytaking into account the adaptive value of each in nature, alsodemonstrate interrelationships between the leve.     

The occurrence of ixodid ticks on wild mink Mustela visonin England and Wales

Abstract. Four species of ticks found to infest 1391 American mink (Mustela vison) in Britain in five years were, in declining order of frequency, Ixodes hexagonus, Ixodes canisuga, Ixodes ricinus and Ixodes acuminatus. Ixodes hexagonus and I.canisuga occurred on 40% and 2.5% of mink respectively. Infestation rates (the proportion of infested mink) of adult females, nymphs and larvae were similar and tended to be lower in summer. The distribution of infestation size (the number of ticks per host) for adult females describes a negative binomial. The mean infestation size of nymphs varied with the sex of the host and was 5.2 for males and 4.2 for females. Mink are competent hosts for /. hexagonus.     

Population ecology and prevalence of tuberculosis in Badgers in an area of Staffordshire

Forty-five badgers representing five social groups were removed from an area in Staffordshire where tuberculosis had occurred in cattle. Prior to removal, the tuberculosis status of the badger population was investigated by screening faeces samples, collected at fortnightly intervals, and badger social-group territories were determined by bait-marking. Samples for cultural and biological examination were taken from the live badgers before euthanasia and detailed post-mortem examination. The adult badger population density was 6-2/km2 and Mycobacterium bovis was isolated from samples taken post mortem from eight (17-8%) badgers. The results are reviewed in relation to previous findings.     

Anatomy and Systematics of Some Polycystididae (Turbellaria, Kalyptorhynchia) from the Pacific and S. Atlantic

Paraustrorhynchus gen.n., P. pacificus sp.n. (California), Antiboreorhynchus novzelae sp.n. (New Zealand) and Gyratrix proaviformis sp.n. (Oregon) are described as new taxa. Additional notes are given on Gyratrix hermaphroditus Ehrbg. (new localities on the N. American Pacific coast), Scanorhynchus forcipatus Karling (new locality in California), Paraustrorhynchus elixus (Marcus) comb.n. and Alcha evelinae Marcus (new localities in California). The taxonomy of the genera and species is discussed. Viewpoints are presented on evolutionary trends and homologous atrial organs in the family Polycystididae.     

Bioassay systems for the pyrethrins; the mode of action of pyrethrum synergists

The components of 'synergistic action' are reviewed in the light of recent work. It has been shown that for sesamin and isobutylundecylenamide at least, synergistic action remains after physical effects are eliminated. The toxicity of the pyrethrins is increased by a factor of three when up to equimolecular proportions of the above synergists are added, further additions having no effect. It is suggested that a surface complex between synergist and insecticide is formed at the peripheral nerve sheath interfaces, resulting in the reorientation of the pyrethrins molecules to give a more efficient discharge of the resting potential at the interface.     

Transmission of louping ill virus between infected and uninfected ticks co-feeding on mountain hares

Abstract. Most of the data on oral infection of ticks by louping ill virus have been obtained from experiments in which animals were infected by syringe inoculation with infectious material. Using infected ticks to mimic the natural situation, we have demonstrated that louping ill (LI) virus transmission can occur from infected to uninfected Ixodes acinus feeding in close proximity on mountain hares (Lepus timidus). Under these conditions the hares developed either low or undetectable viraemias. Highest prevalence of LI virus infection was observed in recipient nymphs which had fed to repletion between days 3 and 7 post-attachment of virus-infected adults; following engorgement, 56% of nymphs acquired virus. These results demonstrate the efficient transmission of LI virus between co-feeding ticks on naive mountain hares. However, when ticks were allowed to co-feed on virus-immune hares a significant reduction in the frequency of infection was observed. Neither red deer (Cervus elaphus) nor New Zealand White rabbits supported transmission of LI virus. The significance of virus transmission between cofeeding ticks on LI virus epidemiology is discussed.