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In addition to the GBSSI isoform of starch synthase described previously, the pea plant contains a second, granule-bound isoform, GBSSIb. GBSSI is abundant in pea embryos and Rhizobium root nodules, is present at low levels in pods and is absent from leaves. Mutations at the lam locus eliminate GBSSI from all of these organs. GBSSIb is present in pods, leaves and nodules and is unaffected by mutations at the lam locus. GBSSI and GBSSIb are very similar in molecular mass, primary sequence, activity and antigenic properties. GBSSIb, like GBSSI, can synthesize amylose in the presence of malto-oligosaccharides in isolated starch granules. However, its role in vivo is unclear. The lam mutation eliminates amylose from the starch of embryos but does not affect the relatively small amounts of amylose-like material in the starch of pods, leaves and nodules. The significance of these results for understanding of the regulation of amylose synthesis is discussed.

Mutants of Pisum sativum L. with seeds containing low-amylose starch were isolated by screening a population derived from chemically mutagenized material. In all of the mutant lines selected, the low-amylose phenotype was caused by a recessive mutation at a single locus designated lam. In embryos of all but one mutant line, the 59 kDa granule-bound starch synthase (GBSSI) was absent or greatly reduced in amount. The granule-bound starch synthase activity in developing embryos of the mutants was reduced but not eliminated. These results provide further evidence that amylose synthesis is unique to GBSSI. Other granule-bound isoforms of starch synthase cannot substitute for this protein in amylose synthesis. Examination of iodine-stained starch granules from mutant embryos by light microscopy revealed large, blue-staining cores surrounded by a pale-staining periphery. In this respect, the low-amylose mutants of pea differ from those of other species. The differential staining may indicate that the structure of amylopectin varies between the core and peripheral regions.

Analyses of seeds from a wide range of pea lines have revealed extensive variation for all of the major fatty acids normally found in pisum. Unlike total lipid content, this variation was not affected by the presence of mutant alleles at the r and rb loci. To allow chemically analysed seed to be used in crosses, which is of particular importance for F 2 seed, a method has been developed by which individual seeds can be analysed non-destructively. This system entails drilling a small hole in the seed, away from the embryonic axis. The small quantity of powder produced by this process can be used for the chemical analysis but does not prevent the seed from being grown to produce progeny. Reducing the sample size had no significant effect upon the compositional analysis of the fatty acids.

SUMMARY A Principal Component Analysis of 39 temperamental attributes on a random sample of 209 infant school children produced four meaningful components. These identified components make an important contribution to an understanding of temperamental organization. A brief questionnaire using the above data has been developed for measuring temperament in infant school children. There are 30 questions with appropriate probes which relate to four components (dimensions): (a) Withdrawal, poor adaptation, dependence, etc.; (b) High activity, intensity, distractibility, etc.; (c) Moodiness, sulkiness; (d) Irregularity. Tentative norms arc provided for the above dimensions.

1. The behaviour of infant school children can be described along two dimensions: conduct disorder and neurotic disorder, which are universally recognizable in other multivariate studies. The additional dimensions which have emerged in this study may be more specific to younger children. The content of these first two dimensions and the form and structure of other dimensions described in various studies are determined by the source of information about the children's behaviour (parents, teachers, etc.), the method of eliciting descriptions of behaviour (checklists, interviews, etc.), the population studied, i.e. age (this study), sex (Collins et al., 1962) type of sample (normal, clinic, etc.), items included in the behaviour scales, and whether item scores are summated (Conners, 1970 and this paper). The first two dimensions appear ubiquitous in form though not in content. 2. A brief questionnaire has been developed for quantifying behaviour in infant school children. It consists of 24 questions with appropriate probes which relate to four dimensions. Tentative norms are provided for the above four dimensions. 3. Probes and definitions of scales are available on request (to I.K.).

A compact, versatile, and reliable hydrophone preamplifier designed for use in multiple hydrophone arrays is described. The preamplifier is used in the frequency range 2 to 5000 cps (−3 db points) and has a dynamic range in excess of 80 db. The equivalent electrical self‐noise is below that of a sea state 0. One vacuum tube for impedance matching and seven transistors for voltage and power amplification are used in the preamplifiers. A total of up to 5 preamplifiers is contained in a cylinder 6 in. in diameter and 12 in. in length. A large amount of negative feedback is used to insure gain stability. The preamplifiers are designed for use with crystal hydrophones with sensitivities greater than −110 db re 1 v/μbar and capacitances of more than 5000 μμf.