Fiftieth Percentile Research Articles

Neonatal mortality risk in relation to birth weight and gestational age: Update

Neonatal mortality risk for all birth weight-gestational age categories has been prepared based on data from an inborn population at the University of Colorado Health Sciences Center for the years 1974 to 1980. There were 14,413 live births and 252 neonatal deaths during this six-year period, reflecting fairly current clinical practices. Based on birth weight alone, neonatal mortality was 0.47% for infants weighing greater than 2,500 gm; based on gestational age alone, mortality was 0.28% for infants greater than 34 weeks. A chart of neonatal mortality risk has been constructed based on birth weights and gestational ages of all these infants. The zones of mortality risk have been color matched to equivalent areas of mortality for the 1958 to 1969 data previously published from the Center for easy comparison. These two populations have also been compared on a graph plotting the predicted mortality at the estimated gestational age and its fiftieth percentile birth weight. This may be useful for consultation by perinatal obstetricians who must make decisions about transfer and care of high-risk mothers before delivery occurs. Where comparisons can be made with other perinatal centers, there is a remarkable similarity in neonatal survival rates, indicating that continuing communication between obstetric perinatologists and neonatologists is a prime factor in reducing mortality, rather than specific new therapeutic procedures at any single clinical center.

Fukuyama-type congenital muscular dystrophy

CONGENITAL MUSCULAR DYSTROPHY in association with developmental central nervous system abnormalities, first described by Fukuyama et al, 1 is now recognized as a distinct clinical entity and is reported to be the second most prevalent form of progressive muscular dystrophy in Japan, 2 The etiology is unknown but both genetic transmission by recessive inheritance and intrauterine infection have been hypothesized? Despite the relatively high prevalence in Japan, the disorder has not been described in Japanese children born in other parts of the world, thus supporting the concept that a local environmental factor could be important in the pathogenesis. We report the clinical, pathologic, and cranial computed tomographic findings in an infant who was conceived and born in Canada with the characteristic features of this unusual disease. CASE REPORT The patient was born of nonconsanguineous Japanese parents who had been residing in Canada for six years. There was no family history of muscle disease or mental retardation. The pregnancy was normal; the mother, a pi'imigravida, ate a normal diet and was not exposed to any toxin or apparent infection. Subsequent to an uncomplicated labor, a female infant weighing 3.2 kg was born. The patient presented to us atage 4 months with hypotonia which was first noted shortly after birth. Examination revealed a hypotonic infant whose head circumference, length, and weight were in the fiftieth percentile. There were no dysmorphic features. She had moderate weakness of facial, neck, and proximal limb muscles. The tendon reflexes were depressed. There was no muscle pseudohypertrophy. Serum ereatine kinase activity was more than 3,000 units/L (normal < 110). Motor nerve conduction velocities and electromyography were both normal. Electroencephalogram showed generalized slow wave activity with occasional sharp waves from the left hemisphere. A quadriceps muscle biopsy revealed variation in fiber size, areas of muscle fiber necrosis with regeneration, and increased endomysial connective tissue compatible with muscular dystrophy (Fig. 1). Histochemistry was unremarkable. The weakness progressed and at age 2 years she deveioped recurrent generalized seizures requiring maintenance anticonvulsant therapy. At 3 years of age she had no speech, was severely mentally retarded, and had an estimated motor developmental age of 4

Daily measurements of atmospheric sulfates in Paris

Sulfate concentration measurements were made from June 1977 through March 1981 at a sampling site located in the center of Paris. The fiftieth percentile for sulfate was approximately 10μg/m 3 and the mean value 12 μg/m 3. Relationships of sulfates with meteorological and chemical quantities were studied. Correlations with SO 2 and fine suspended particulates were higher in winter (October to March inclusive) than in summer (April to September inclusive). The highest concentrations were observed especially in winter, when wind speed was less than 2 m/s and/or fog or important morning haze occured, but for these days SO 4/SO 2 ratios were not higher than for the other days. On the other hand, in summer SO 4/SO 2 ratios were abnormally strong for preferential wind directions. Measurements at suburbs sampling sites proved that the sulfate concentrations were at the same time very homogeneous in the Paris metropolitan aerosol ; a station exposed to diesel exhaust did not show significant increase in sulfates.

Human Factors for Portable Products

The parameter of weight was investigated to determine the correct poundage of a portable product for the 5-95 percentile male and female consumer. The concept of portability appears to be culturally inspired such that men and women do not differ in the amount of weight which they feel is portable. Men, however, tend to use approximately 30% of their maximum isometric arm strength when carrying what they feel to be a portable object, while women utilize slightly over 40% of their maximum isometric arm strength to carry the same weight. For the subject group as a whole the correct maximum portable weight ranges from 4.5 kg. at the fifth percentile to 10.2 kg. at the ninety-fifth percentile. The fiftieth percentile maximum portable weight was found to be 7.3 kg. In addition wrist rotation strengths in the vertical upright position used for one-handed carry were recorded for the 5-95 percentile male and female to aid in the determination of correct handle placement and case balance.

A new graph for insertion of umbilical artery catheters

THE LENGTH of insertion for umbilical artery catheters has been based on the graphs tabulated by Dunn 1 for total body length and shoulder umbilical length. Despite frequent use, these graphs have not been critically evaluated and have several potential limitations. They are based on the anatomic landmarks of the pathologist (the diaphragm) rather than those of the clinician (vertebrae). The original study included only eight of 25 patients with TBL _< 40 cm (fiftieth percentile for patients weighing 1,200 gin); and used only postmortem patients. Using live patients and including a larger number of low-birth-weight neonates, we re-evaluated Dunn's graphs. In addition, new graphs for catheterization were calculated and their accuracy determined. METHODS

Skeletal maturity in Danish schoolchildren assessed by the TW2 method.

Skeletal maturity was assessed from hand-wrist radiographs in a sample of 3,817 Danish schoolchildren aged 7 to 18 years using the new version of the bone-specific Tanner-Whitehouse scoring system, the TW2 method. In most of the age groups in both sexes the distributions of the bone maturity scores displayed marked departures from normality; percentiles for the scores were therefore counted from the raw data. On the average, over the total age range, the differences between the age equivalents (bone ages) for the fiftieth percentile and chronological age were close to zero in both sexes, indicating good agreement with the British standards. However, in the individual age groups, and in particular at adolescence, characteristic divergences from the standards occurred, apparently reflecting the developmental spurt.

Sulfate concentrations in the southwestern desert of the United States

Filter samples of the Southwestern Desert aerosol were analyzed for sulfur using proton induced X-ray emission. These samples were obtained during the winter of 1976–1977 when a series of Great Basin Highs dominated the synoptic weather maps. The lowest concentration of sulfur was 0.03 μm −3, (0.09 μg m −3 sulfate). The fiftieth percentile for sulfur was approx 0.250 μg m −3 (0.750 μg m −3 sulfate).

Human thoracic anatomy relevant to implantable artificial hearts.

The objective of this study is to define the human thorax in a quantitative statistical manner such that the information will be useful to the designers of cardiac prostheses, both total replacement and assist devices. This paper pertains specifically to anatomical parameters relevant to the total artificial heart. Methods were developed for generating an integrated, statistical model of the anatomical structures within the human thorax. These methods involve definition of the anatomy in four areas: chest wall, pericardium, vascular connection locations, and great vessels. Results are presented in three dimensional scale views of the human thorax showing the main features pertinent to cardiac prosthesis implantation. Statistical variability of this data is also included. Measurements were obtained from a number of sources and represent both normal and diseased patients. The ERDA total artificial heart was shown to successfully fit the fiftieth percentile adult male human.

Blood acid-base balance at birth in neonates from labors with early and late rupture of membranes

The purpose of this study was to determine whether the early artificial rupture of the amniotic membranes performed to shorten the duration of an otherwise normal labor and delivery might have potentially deleterious effects on the fetus that would be reflected in the neonate. In 38 infants delivered at term, acid-base balances and O2 and CO2 pressures were obtained in umbilical arterial and venous blood at birth, prior to the first inspiration. For the purpose of the study the infants were divided into two groups: group I infants were born after a normal labor in which the amniotic membranes were permitted to rupture spontaneously at full cervical dilatation; group II infants were born after a labor in which the membranes were ruptured artificially when cervical dilatation was 4 to 5 cm. There was no evidence of fetal distress, and all infants were vigorous at birth. The pH of umbilical venous blood was greater in the group with late rupture of the membranes (fiftieth percentile [P50] = 7.36) than in those born after early amniotomy (P50 = 7.30) (p less than 0.01). The pH values of umbilical arterial blood were also higher in the group I infants (P50 = 7.31) than in those born after amniotomy (P50 = 7.25)(p less than 0.025). These differences were also observed in the 19 neonates in whom the cord was not encircled around the neck at the time of birth. The PCO2 in umbilical venous blood was less, and the hemoglobin saturation was greater (P less than 0.05) in group I infants than in those of group II. It is possible that the influence of early amniotomy on fetal pH may be deleterious in infants born after high-risk pregnancies in which the uteroplacental circulation is impaired.

Shifting linear growth during infancy: Illustration of genetic factors in growth from fetal life through infancy

A percentile linear growth chart, from the third to ninety-seven percentiles, was derived from longitudinal data on 90 normal full-term infants of middle class suburban families, and the individual growth curves of each infant was contrasted to the growth chart for the entire group. Individual shifting in growth rate was noted in two thirds of the infants. To better determine the timing and nature of these shifts in linear growth, a search was made for otherwise normal full-term infants who were at or below the tenth percentile for length at birth and who moved up to the fiftieth percentile or better by age 2 years and those who were at or above the ninetieth percentile at birth and moved down to the fiftieth percentile or less by 2 years of age. Those shifting upward had accelerated linear growth soon after birth; they achieved a new "channel" at a mean age of 11.5 months. Those shifting downward did not decelerate until after the first three to six months; they achieved a new channel by the mean age of 13 months. These findings plus the correlation coefficients relating parental size to the length of the infant at birth, one year, and two years of age are compatible with the following statements: Birth length relates predominantly to maternal size whereas by 2 years of age the length correlates best to mean parental height, reflecting the genetic growth factors of both parents. Those infants "catching-up" after birth usually do so in early infancy, whereas those "lagging-down" tend to do so in midinfancy.

Thoracic-Pelvic-Phalangeal Dystrophy

The thoracic-pelvic-phalangeal dystrophy (TPPD) is a heritable condition with an autosomal recessive mode of genetic transmission. This entity has been called familial asphyxiant thoracic dystrophy (6), asphyxiating thoracic dystrophy of the newborn (15), infantile thoracic dystrophy (3), and Jeune's disease (16). Individuals with this condition have constriction of the thorax and short extremities and characteristic changes in the fingers and toes. The small thoracic cage may contribute to respiratory death in infancy, and associated renal disease may be a cause of death in childhood. Because of the serious medical implications of this condition and its genetic nature, with a 25 per cent chance of each subsequent pregnancy's resulting in an affected child, it is important to establish the correct diagnosis. Material The analysis in this article is based on 2 cases seen personally, 3 patients whose radiographs were seen in consultation, and 43 cases published in the literature, 27 of which included, in my opinion, adequate documentation to establish a radiographic diagnosis (4): that is, in addition to a chest radiograph, there were included in the article radiographs of the pelvis and, in some instances, of the hands. Case Reports Case I: A newborn female with a very narrow thorax, short extremities, and polydactylia of the hands and feet died after several gasping respirations. No autopsy was performed. Postmortem radiographs are discussed in the section on radiographic features. Case II: A newborn male was examined because of mild generalized central nervous system depression and a questionably enlarged liver. The clinical measurements at birth were: length 51 cm (approximately the fiftieth percentile for age), head circumference 37.5 cm (the ninety-seventh percentile for age), chest circumference 31 cm (between the tenth and twenty-fifth percentiles for age). Radiographic examination of the chest and abdomen at three days of age was interpreted as showing the changes of TPPD (see section on radiographic features). After the radiographic study, it was felt on clinical examination that the thorax was somewhat constricted. The signs of central nervous system depression disappeared, and the patient was discharged at five days of age. At no time in the hospital or during the subsequent month were there any respiratory symptoms. The patient was then lost to follow-up. Case III: A male who was clinically well was first seen at nineteen months of age because of disproportionately short limbs. A radiographic study which was made at this time is discussed in the section on radiographic features. When 2 1/2-years-old, the patient was seen by his physician because of sleeping problems, and it was noted that the hemoglobin was 8.2 g per 100 ml. This rose to 10.0 g per 100 ml on iron therapy. At the age of three years and one month he had several episodes of epistaxis and was found to be pale.

Iatrogenic hypopituitarism in craniopharyngioma: Unexplained catch-up growth in three children

Nine consecutive children with craniopharyngiomas were studied who had relatively normal pituitary function prior to operation. Surgical attempts to remove the craniopharyngiomas were frequently followed by a loss of thyroid stimulating hormone, evaluated indirectly by the butanol extractable iodine, and by failure of adrenocorticotrophic hormone as reflected by a fall in urinary 17-hydroxycorticosteroids and a loss of previously normal SU-4885 responsiveness. In addition, diabetes insipidus, which had not been present preoperatively, invariably followed stalk section which was often necessary during surgery. Despite the postoperative appearance of diabetes insipidus and of thyroid-stimulating hormone and adrenocorticotropic hormone failure, three of ten patients showed “catch-up growth” postoperatively. One of the three had a growth spurt which carried him from below the third up to the fiftieth percentile in 1 1/2 years after operation. He showed no increase in serum growth hormone during arginine or insulin provocative tests. The growth spurts in these three patients are difficult to explain in view of the loss of integrity of their hypothalamic-pituitary pathways.

Phenylketonuria: Evaluation of therapy and verification of diagnosis

Twelve patients were studied who had been placed on a low-phenylalanine diet before 2 months of age because of hyperphenylalaninemia. The failure of tyrosine blood levels to rise significantly after a phenylalanine load was considered confirmation of the diagnosis of phenylketonuria. The height of each of the 12 patients was less than the fiftieth percentile and 3 were under the third percentile. The failure to thrive was correlated with a plasma phenylalanine level below 3 mg. per 100 ml. One child developed the phenylalanine deficiency syndrome.

Roentgenographic findings in Fanconi's anemia.

Atriad of severe refractory hypoplastic anemia with pancytopenia, brown pigmentation of the skin, and multiple congenital anomalies was first described by Fanconi (9) in 1927. He reported three siblings who presented this triad which is now known as Fanconi's syndrome or Fanconi's hypoplastic anemia. The condition is rare, about 90 cases having been reported up to 1960, according to Nilsson and others (1–11, 14–17, 19–21, 23). Its distribution is world-wide; it has been reported throughout Europe and the United States as well as in Japan, Turkey, South Africa, and South America. There is no racial or geographic preponderance. The disease is somewhat more common in males than in females in a ratio of approximately 2 to 1. The purposes of this report are to present the clinical and roentgenographic findings in 14 cases, with case histories of 4 of them, to review briefly the clinical manifestations, particularly as they relate to roentgenographic findings, and to discuss the roentgenographic diagnosis of this syndrome. Case Reports Case I: This 9-year-old white female was admitted to University Hospitals for the first time on Sept. 25, 1965, with a chief complaint of cough and fever, which had developed two weeks prior to admission. On physical examination she was found to be 51.5 inches in height with a weight of 54 pounds. Height was in the fiftieth percentile for an eight-year-old, and weight was in the fiftieth percentile for a seven-year-old. The head circumference was 18.5 inches, which is in the fiftieth percentile for an 18-month-old (microcephaly). The child was extremely pale but exhibited a generalized bronze pigmentation. She had syndactyly of the second and third toes bilaterally and was unable to bend her left thumb at the distal phalanx. Blood taken on admission revealed white blood cells 3,500, 17 seg-menteds, 2 bands, 70 lymphocytes, and 11 monocytes. The platelet count was 9,000. Hemoglobin was 3 g per 100 cc, and hematocrit, 8.0. An admission chest film showed bronchopneumonia on the left. Findings on intravenous urography were within normal limits. Skull roentgenograms demonstrated microcephaly (Fig. 1). Skeletal films showed minimal shortening of the right first metacarpal and left first proximal phalanx as compared to the opposite sides (Fig. 2). Films of the feet showed only soft-tissue syndactyly. Several transfusions of packed cells were given as soon as possible after admission. The patient improved considerably following the transfusions, and the hematocrit went to 31. Bone-marrow aspiration and subsequent biopsy revealed a moderately hypoplastic marrow, involving chiefly the megakaryocytes and white cell series. A diagnosis of Fanconi's anemia was made. The family history was interesting and pertinent. A 12-year-old sibling had died in 1962 with Fanconi's syndrome. This sibling had aplastic anemia, an absent thumb, microcephaly, and an absent kidney.

Anomalous cephalic venous drainage in association with aneurysm of the great vein of Galen.

Aneurysmal dilatation of the great vein of Galen occurs as a result of increased venous flow from an adjacent arteriovenous malformation. Excluding 15 reported aneurysms of less than 1.5 cm diameter, there are 47 previously reported instances of this condition (5, 12—14, 16, 20, 22, 24, 25, 27, 30). Eight patients showed an abnormality of cranial venous flow secondary to dural sinus occlusion (6, 9, 11, 12, 21, 26, 27, 31). The following case represents another report of such an association of vascular anomalies. Case Report L. S., an 11-year-old male, was referred to the plastic surgery unit of the University of Florida Teaching Hospital, Gainesville, Fla., for possible cosmetic repair of prominent superficial forehead veins. At one month of age, with no preceding infection or trauma, a soft, painless mass appeared at the glabella. The mass became more prominent with time, but never caused symptoms. At twenty months of age, the patient underwent bilateral carotid arteriography, accomplished without sequelae. An intracranial vascular malformation was diagnosed, and it was concluded that the associated facial lesion should not be surgically approached. At seven and a half years of age, repeat bilateral carotid arteriography disclosed substantially the same abnormalities as the earlier study. The family history was not significant. The patient acknowledged infrequent, mild, poorly localized headaches of brief duration. He denied hearing a bruit and had no symptoms suggestive of increased intracranial pressure. On examination at the University of Florida, the blood pressure was 110/60, and the pulse rate was 80 per minute. There was equivocal cardiomegaly, without murmurs, and the head circumference was in the fiftieth percentile for age. In the subcutaneous tissue about the eyes a soft, plexiform mass extended over the bridge of the nose onto the forehead and downward onto the medial cheeks (Fig. 1). The overlying skin had a slight violaceous hue. There was no associated ulceration. The mass was easily compressible, and a thrill was palpable at the medial border of the left eye; a continuous bruit with systolic accentuation could be heard over the area. A venous hum was audible over the calvarium more posteriorly. Funduscopic examination revealed venous engorgement and indistinctness of the disk margins; there were no hemorrhages or exudates. The remainder of the examination was normal. Skull roentgenograms showed bilateral enlargement of the superior orbital fissures (Fig. 2), no pathologic intracranial calcification, and no evidence of increased intracranial pressure. Later radiographs (Chamberlain-Townes, Law) demonstrated a vascular groove in the occiput housing the transverse sinus and sclerotic sinus plates demarcating the anterior extent of the sigmoid sinuses. On special jugular foramen views, the jugular canals were symmetrically diminutive, particularly in their lateral portions where the jugular bulb is normally housed.

Cortisol production rate. VI. Hypoglycemia in the neonatal and postneonatal period, and in association with dwarfism

Cortisol production rates were estimated in patients with transient neonatal hypoglycemia, postneonatal hypoglycemia, and hypoglycemia with dwarfism. In the first group, four low-birth-weight males had abnormally low rates. In the second group, cortisol production rates were in the normal range. Low to low-normal rates were found in the group of dwarfs. Three of five older dwarfs had a history of low birth weight for gestational age. Of these, two were the smaller members of two sets of twins; one had documented neonatal hypoglycemia. These three patients may have had hypopituitarism in utero. Of the entire group of 23 patients, only one was above the fiftieth percentile in height, and 19 were below the twenty-fifth percentile. Growth failure in most of these patients with hypoglycemia is unexplained.

Hypoglycaemia in childhood.

HYPOGLYCAEMIA in children may cause listlessness, inattention, pallor, stupor, convulsions and coma, which may be accompanied by tachycardia and sweating. Such non-specific symptoms as cyanotic attacks, reluctance to feed, irritability, convulsions, jittery limb movements and depression of the Moro reflex may occur in the hypoglycaemic newborn infant. A major part of these clinical patterns arises from the neuroglycopenia which is caused by hypoglycaemia. Hypoglycaemia has been recognised in childhood for over forty years (Ross and Josephs, 1924) and yet its true incidence in the newborn and older child is still difficult to assess today. Forty cases occurred amongst children of all ages in a one hundred and thirty bed unit over a twelve year period (McQuarrie, 1954) and twelve neonatal cases were found among six thousand newborn infants (Neligan, Robson and Walton, 1963). The incidence of symptomatic hypoglycaemia has been found to be no less than 6% among premature infants, and as high as 15% in infants of birth weight less than the fiftieth percentile for gestational age (Wybregt, Reisner, Patel, Nellhaus and Comblath, 1964). Many different methods of blood sugar estimation have been used, and early less specific reduction methods (Folin and Wu 1920; Hagedorn and Jensen, 1923) tended to give higher figures than more specific reduction methods (Somogyi, 1952) and the glucose oxidase method (Marks, 1959). It is therefore difficult to define hypoglycaemia in terms of a blood glucose level. There is little doubt that the threshold for symptoms of neuroglycopenia varies from patient and from time to time. In the newborn a blood glucose level of under 20 mg./ 100 ml. or even below 10 mg./100 ml. may occasionally occur without symptoms, and many older children are not affected unless the level is under 40 mg./100 ml. Endocrine deficiencies causing hypoglycaemia are rare in childhood. Fasting hypoglycaemia was found in 29.3% of seventy-five cases of hypopituitarism, and hypoglycaemic symptoms occured in 9.7 %. In 37.5% of this series hypoglycaemia followed a glucose load and 66.7% were sensitive to insulin (Brasel, Wright, Wilkins and Blizzard, 1965). The T. P. MANN, M.D., F.R.C.P. Royal Alexandra Hospital for Sick Children, Brighton

Radionuclide Doses to Infants and Children

The variation in the average dose from an internally deposited radionuclide with the radionuclide, its chemical form and route of administration is fairly well known. Maximum permissible dose levels are normally based upon the administration of a given quantity of radionuclide to “standard man”, a hypothetical adult of average weight and height, as well as chemical composition. This study considers dose levels for infants and children. A series of standard children of various ages was derived by supplementing values of the fiftieth percentile for heights and weights of certain ages with pertinent information on organ weights and physiology. Age groups selected for this study include: newborn, 1, 5, 10 and 15 years old. Average absorption doses in mrad/μc administered were then calculated for the whole body and/or critical organ using the general beta and gamma dose formulae. The average whole body doses ranged from 10 to 20 times greater in the newborn than standard man for a given quantity of administered radioactivity. Furthermore, since infants and children breathe more air on a per weight basis than an adult and since their water intake is also greater on a per weight basis, maximum permissible concentration guides based upon standard man do not apply to younger individuals.

Growth rate of children with intractable asthma: Observations on the influence of the illness and its therapy with steroids

Anthropometric data were collected on 302 intractable asthmatic children, 6 to 16 years of age, observed at the Jewish National Home for Asthmatic Children in Denver, from July 1, 1958, to Dec. 31, 1960. Admission heights of 83 per cent of these children fell below the mean, or the fiftieth percentile, for their respective age and sex and, in 20 per cent or 10 times more than normal, the heights were more than two standard deviations below the mean. Weights generally corresponded with heights. Bone age, paralleled the heights rather than the chronological age, although a fairly wide range of values was noted. The size of parents did not seem to be primarily responsible for the observed growth deficit among asthmatic children. A review of the individual pre-admission histories indicated that an earlier onset of asthma or a longer duration of the illness was not associated with a significantly greater degree of growth retardation. A history of continuous administration of anti-inflammatory steroids before admission was more common among the smaller children, while shorter courses of steroids, not exceeding 50 per cent of any year of life, did not seem to affect growth adversely. During the 18 to 24 months of residence at the Home, the presence of asthmatic symptoms did not diminish height increments, neither did brief courses of steroids affect growth. Continuous maintenance steroid therapy, given only in severe cases of asthma uncontrollable by other means, was associated with a significantly reduced linear growth rate. A comparison of the growth suppressing effect of prednisone and cortisone indicated that children requiring mean daily doses of prednisone, exceeding 6 mg. per square meter of body surface, exhibited reduced lineal growth rates. On the contrary, children receiving cortisone, in mean daily doses exceeding 50 mg. per square meter, exhibited normal growth increments. The control of asthma, however, seemed to be less satisfactory with cortisone than with prednisone, in what are considered equivalent amounts. A considerable individual variation was noted in growth rates among children in all categories and especially among the adolescents. Preliminary results of pituitary function assays, by means of serum sulfation factor activities, are reported, and the need for additional studies is emphasized.

PLACEMENT PROBLEMS AMONG ENGINEERING APPRENTICES IN PART‐TIME TECHNICAL COLLEGE COURSES

Summary. Three groups of part‐time day release students taking first year Ordinary National Certificate Classes in engineering were given a verbal and non‐verbal intelligence test (N&gt; 1000). On the verbal test the mean score was only slightly above that for the population as a whole, but on the non‐verbal test 89 per cent. were at or above the fiftieth percentile with 27 per cent. in the top 10 per cent. of the population. Recent attempts to improve the selection of Ordinary National Certificate students appear to be unrelated to intelligence test scores, as the results obtained in two different areas between 1950 and 1957 show no significant differences. Fifty per cent. had attended secondary modern schools as against 73 per cent. of the whole school population in the same age range. Seventy‐five per cent. had fathers in skilled and managerial jobs, compared with a national average of 53 per cent. In 1957, only 18 per cent. of those not in full‐time education were attending part‐time day classes.The educational and sociological implications of these figures are discussed in relation to manpower problems. An increase in the number of such students must increase the proportion from secondary modern schools and unskilled homes, so that the problems associated with teaching young people of poor verbal ability are unlikely to diminish.