Strong Morphological Differences Research Articles

Phoretic association of some AfricanCyaneolyttaPéringuey 1909 with carabids, and morphology of first instar larvae in Meloini (Coleoptera Meloidae)

The phoretic association between larvae of the genus Cyaneolytta Peringuey 1909, and those of another unclassified meloine with Coleoptera Carabidae of the Anthiini tribe is discussed. So far these associations have been considered to be only by chance, but probably they are connected with as yet unknown aspects of the larval biology. Some hypotheses about the possible hosts of Cyaneolytta, with particular attention to the Isoptera and to the Coleoptera Carabidae, are presented. However, it is possible that some species are parasitic on other orders of insects. The strong morphological differences of the first instar larvae are emphasized, and the larvae of three species are described. Perhaps the larva of an unclassified meloine can also be placed in this genus. On the basis of the morphology of the first instar larvae the genera and subgenera of the Meloini tribe are discussed, and a new key for their classification is proposed.

Present-Day Geomorphological Processes on Prins Oscars Land, Svalbard

My work in the team on Prins Oscars Land was to study the present-day geomorphological processes and their effects, in an area of crystalline rocks and rolling landforms, with glacial forms located mainly along the fiords. Most of the work was done on the eastern side of Rijpfjorden. The various processes are discussed in separate sections. Particular interest is given to frost weathering, which is slow at present, but has probably been more important in some past period, to judge from well-developed block fields and from sequences of raised beaches produced from solid rock by frost weathering combined with marine processes. In a special section patterned ground and mass movement, mainly of tundra polygons and rock glaciers, are presented.Main attention is devoted to the marine processes, the most efficient processes in recent time, producing erosion forms in solid rock and wide fields of raised beaches. Forms related to marine processes are much better developed in the outer parts of the fiords, while the inner parts have almost unchanged glacial forms, particularly in solid rock. The strong morphological differences between north and south may indicate a clear difference in the time of deglaciation. On the peninsulas of the area there is a series of talus cones eroded by the sea. As this may indicate a present transgression, an appendix is added in which similar forms from all Svalbard are examined. The frequency of these is high and well-distributed, and most probably indicates a present land depression. Some archaeological data give a similar picture.

The Voyager 1 EUV spectrum of the Io plasma torus

The Voyager 1 EUV spectrum of the hot Io plasma torus has been analyzed by using a collisional model. The estimated effective electron temperature of the central dense region of the plasma is 8 × 104 K. The torus half width number densities (cm−3) obtained from the model calculation are O II (50), O III (340), O IV (<17), S II (44±20), S III (160), S IV (220), S V (≤11), and K III (≤80). The relative oxygen/sulfur number densities are ΣOn/ΣSn ≃0.9. Comparison of the model calculations with other spectroscopic observations that can be clearly identified as originating in the hot plasma torus shows satisfactory agreement. However, the EUV observations show strong morphological differences with recent ground‐based observations of S II emission, raising questions concerning excitation mechanisms and radial dependence of the observed characteristics. The ion densities indicated by the EUV data analysis show distinct differences with the in situ Voyager 1 plasma science estimates.

The chromosomes and relationships of Welwitschia mirabilis

W. mirabilis is unique in the plant kingdom by having a very peculiar habit. Its karyotype is very asymmetrical. Two of the chromosomes in the complement are satellited and this coincides with 2 nucleoli in the metabolic nuclei. The longest pair in the complement is nearly 3.25 times longer than the shortest pair. Between the two extremes there is a gradual transition in size in the karyotype. Such a karyotype has no relation (quantitative or qualitative) with those in Ephedra and Gnetum. Arguments have been advanced against interrelating Ephedra and Welwitschia through hermaphrodite “flowers”. Such flowers appear to be due to the sex polymorphism ensuing as the result of tetraploidy (in originally diploid-dioecious species) and do not represent therefore the ancestral condition. Only after these abnormalities are discovered in diploids they will represent atavistic mutations and then alone phyletic reliance can be placed in them. In view of the strong morphological differences the few resemblances between the three genera are possibly due to parallel evolution, because many of these are also found in other gymnosperms. The best arrangement is to treat the three genera as belonging to three distinct orders under one class.