The Autor gives a genetic interpretation of homosexuality. A first division may be done between homosexuality cum materia and sine materia. For instance we speak of homosexuality cum materia in the case of such adrenogenital syndromes in which an augmented secretion of androgens may orientate the females towards the male direction, including psychological inversion. As for homosexuality sine materia, the Author reports the twin data by Kallman demonstrating, by means of a new statistical analysis, the presence of hereditary factors. According to the Author such cases could be microforms of inherited endocrine diseases originated by an enzyme affection, or equivalents of inherited psychiatric diseases.

The Authors describe a case of aplasia of the upper limbs in a discordant MZ twin pair. According to the individual and genealogical findings, and especially to the fact that these female MZ twins are discordant, as well as to the caryologic finding, the Authors conclude that the malformation is not genetically induced but possibly originated by blastophthoric factors during the first and second month of fetal life.

Weights of mineralized dental tissue have been determined in incisors dissected from ten pairs of twins failing to survive beyond 7-8 months' gestation. Logarithms of weights were compared as ratios (lower/upper) with data from foetuses of similar development. Intra-twin differences were thus shown to be significantly less than inter-twin differences when comparing central incisors. Lateral incisors were too variable to allow this demonstration. The linear regression equation combining logarithms of lower and upper central incisor weights was suitable for estimating foetal age to within one week of the recorded age.

A family of Iranian-Jewish origin with two hereditary enzymatic defects in the red blood cells, catalase deficiency and glucose-6-phosphate dehydrogenase deficiency, is described. The two enzymatic defects were inherited independently of each other. The findings are compatible with a transmission of the catalase deficiency by an autosomal gene of incomplete dominance, the homozygous state resulting in severe catalase deficiency and the heterozygous state in intermediate catalase deficiency.

The clinical and histologic observations in an 18-year old male with osteopoikilosis are described. Twenty-four of the proband's relatives were roentgenographed; films were taken of their pelves, hips, knees and elbows. The father was found to have osteopoikilosis, but none of the others were affected.

It has been attempted to figure out how osteopoikilosis is transmitted by a study of the family data given in the literature. Though it is realized that these data are biased because of their selective nature, it is suggested that osteopoikilosis is inherited as an autosomal dominant disease.

Two personal observations are presented, the former including a pedigree showing both on the maternal and paternal side isolated symptoms of the Ellis-van Creveld syndrome, and the latter consisting in an affected child ensued from a consanguineous marriage, his parents being first cousins. The cases of the literature in which the hereditary component is evident (28 in 49) are also examined. The most significant data from a genetic standpoint are discussed, i. e. the presence of isolated symptoms in the families of the patients, the consanguinity in the parents, the presence of the syndrome in different members of the same sibship. As a conclusion the recessive inheritance, through an autosomal polyphenic gene, is confirmed.

The statistical data on the malformation occurred in Italy from 1956 to 1958 have been examined. It has been seen that their number is almost constant (i. e. some 1,500 per year). The ratio of alive malformed to dead malformed is of 3:1, but the number of deaths by congenital malformations increases considerably during the first year of life, mostly due to inner organ malformations, non detectable at birth.

50% of the cases of harelip die during the first year of life. The most serious malformations are those concerning the central nervous system, while the most common ones, are those affecting the locomotive apparatus.

The number of malformations has not been influenced by the very insufficient diet during the four years of war, neither by the 1957 « asiatic influenza ». The malformation index, furthermore, appears almost constant in the time and in the various regions, showing the highest figure in Lucania and Friuli (3.05) and the lowest ones in Campania (0,89), Sicily and Liguria (1.21).

The Author has studied the Kell, Cellano and Duffy factors in a selected sample of the roman population.

A comparison of the already known data for the rest of Italy shows that the Kell factor has a higher frequency, as compared to that found by other Authors in other regions, while the Duffy factor appears to be less frequent.

A survey has been made of the birth records of 846 twins (415 pairs and 6 sets of triplets) born in Catania between January 1st, 1959 and May 31st, 1962, with the purpose of establishing the degree of mortality in twins in the first year of life. The results indicate a low degree of still-birth (5%). Identifying the neonatal period with the first week of life, the neonatal mortality is of 8.9%. This percentage undergoes a little reduction (1.9%) when we consider as neonatal period just the first day of life, the twin mortality being lower in the subsequent days of the first week. Except that of the 1st day, the higher frequency of mortality (19%) occurs between the 12th and the 16th day, which is considered a critical period in the first month of life in twins. In the remaining 11 months of the year the mortality degre is low (51 deaths in 680 twins survived to the first month). At the end of the year in 63.1% of the considered pairs both twins were still alive. In six of the 43 pairs with both components dead, both twins died between the 13th and the 25th day, with an interval of 24 hours. The spontaneous death of twin pairs, occurring sometimes simultaneously or with a brief interval in the first month of life, may give rise to judiciary mistakes.