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Summary A gross and quantitative study of the muscle and connective tissue and elastic tissue has been carried out on a series of 78 abnormal ureters in children. The ureters have been classified into 5 classes: (A) normal; (B) ureters with irregular dilatations; (C) slightly dilated ureters with muscular hypertrophy and hyperplasia; (D) elongated and dilated ureters with muscular hypertrophy and hyperplasia but probably decompensated; (E) grossly distended and elongated ureters having an increase in elastic tissue but with no comparable muscular hypertrophy or hyperplasia. Ureters showing structural changes do so uniformly throughout their length and no local anatomical deformities were found to account for the irregularities in the ureters of Class B. Structurally incompetent uretero‐vesical junctions are only associated with ureters of Classes D and E. All abnormal ureters show varying degrees of muscular hypertrophy and hyperplasia. It is suggested that the form of the ureter is related to whether or not the muscular hypertrophy is adequate to compensate for the increased luminal diameter.

New information on the electron and hole wavefunctions in InAs±GaAs self-assembled quantum dots (SAQD) is obtained from photocurrent spectroscopy of the quantum confined Stark effect. We show that the hole is localised towards the top of the dot, above the electron, an alignment opposite to that predicted by all previous theories. By means of envelope function calculations we show that this alignment can only arise if the nominally InAs dots have a graded Ga x In 1Àx As composition with x decreasing from base to apex, and a relatively flat, non-pyramidal shape. In the light of these results most if not all previous modelling of the electronic structure of InAs SAQD needs to be re-examined. The mechanisms involved in the photocurrent process are also discussed.InAs/GaAs self-assembled quantum dots (SAQD) provide nearly ideal examples of zero-dimensional (0D) systems with a fully quantized, discrete energy spectrum of electrons and holes, and have very favourable opto-electronic properties [1]. As a result they have been intensively studied in recent years. However, in spite of the large amount of work, very little experimental information is available on the forms of the electron and hole wavefunctions in such structures. Furthermore, the reliability of theoretical studies which model the carrier wavefunctions in SAQD [2 to 5], is questionable because of the lack of precise structural information.In this paper we employ photocurrent spectroscopy to measure absorption-like spectra in InAs/GaAs SAQD. Although they are the most fundamental optical probe of electronic properties, absorption spectra are difficult to obtain for SAQD. Calorimetric absorption spectroscopy [6] requires very low temperatures and results in broadened spectra; direct absorption spectroscopy [7] requires very sensitive detection techniques. In addition, photoluminescence excitation spectroscopy, commonly employed to measure absorption spectra in quantum wells is dominated by phonon related features in SAQD [8]. Photocurrent measurements suffer none of these drawbacks; they provide a P. W. Fry et al.: Quantum Confined Stark Effect 269 1 ) Corresponding author;