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The breeding biology of the House Martin Delichon urblca (L) is described/ with particular reference to the influence of variation in the abundance of aerial insects. The selection of food items from the available resources is explained in terms of a prediction strategy which demonstrates that the Martin consistently maximises the efficiency of food collection,, The timing of the breeding season and breeding success are respectively shown to be closely associated with the development of the aerial phase of several insect populations and with food abundance. A hypothesis is presented, with some supporting evidence, which describes the potential selective forces acting on broods both smaller and larger than the most frequent natural brood sizes which would possibly inflict a disproportionately large mortality on these extreme brood sizes and also on the adults involved in rearing them. This is particularly relevant: to those species where artificially enlarged broods or the largest naturally occurring broods are more productive than the most frequent brood sizes, as is the case in this study. Differences in food and feeding station are described which ensure a degree of ecological isolation between aerial feeding birds in Britain.

The thesis describes the direct measurement of adsorption of electrolytes on some oxide surfaces and electrokinetic measurements made on the same systems. Oxides with the spinel structure were chosen so that variation of lattice constant and chemical properties could be controlled and the extent of their effects on adsorption examined. A number of spinels were prepared from the pure parent oxides or coprecipitated hydroxides. The surface areas of some samples of the spinels, prepared for adsorption studies, have been measured by a B.E.T. isotherm method. Propane was used as the adsorbate gas, conveniently giving pressures of the order of 10 cm at solid carbon dioxide temperatures. The eleotrokinetic behaviour of two of the spinels, MgA1204 and NiAl204, was studied by the streaming current technique. Methods of analysing small quantities of solutions of divalent metal electrolytes at low concentration were devised so that the adsorption of these electrolytes could be determined. The results are less satisfactory than expected; in a number of cases the total cation and anion concentrations did not agree, indicating at least a partial failure of the analytical technique.

This report is a study of rocks that are exposed at the surface within the Gray Horse area; Osage County, Oklahoma. The primary objective of this investigation was to map and describe in detail, rock units of Upper Pennsylvanian and Lower Permian age, which constitute the surface rocks of this area. Par­ticular emphasis was placed on areal distribution, changes in lithology, in thickness, and in faunal assemblages along the strike of the beds. In carrying out such an objective a secondary purpose is realized: that of determining the persistence of thin rock units that extend from southeastern Nebraska across Kansas and into north-central Okla­homa as they grade into the basinal deposits in central and southern Oklahoma.