The problem of the familial incidence of cancer has been studied on the basis of the genetical researches of the last ten years on leukemia, cancer of the breast, uterus, prostate, bladder and stomach. The conclusion has been reached, except for the cancer of the bladder, of the existence of a significant familial incidence of cancers.

The difference in nuclear structure between male and female tissues in man has been examined in liver tissue from three embryos of each sex. The so-called sex chromatin consists of a large heterochromatic segment of the X chromosome, thus existing in duplicate in female diploid cells. The two segments have a tendency of juxtaposition resulting in a larger heterochromatic body in female than in male cells. Beside the large heterochromatic segment the X chromosome has, in the tissues studied, a euchromatic segment attached through a small terminal heterochromatic knob to a nucleolus. In male cells the euchromatic segment of the X chromosome is often joined terminally to a small heterochromatic segment believed to belong to the Y chromosome.

Two types of Polydactyly are described. Preaxial polydactylism is a relatively rare trait, involving a varying degree of duplication of the thumb. X-ray evidence is presented for this condition in a baby girl when first born and 5½ months later, showing the nature of its development. X-ray of the parents revealed that the mother was affected and the father was normal. Evidence points to the possibility that this trait follows a simple autosomaly type of inheritance. Postaxial polydactyly, the more common type, generally involves a duplication of the little finger (5th) with a varying degree of expression. A pedigree of a Negro family is described and X-ray evidence for this trait is given. Each duplicated miniature finger consists of two small but well formed phalanges. The trait seems to be transmitted as an incomplete dominant.

On the ground of an inquiry, carried out on pedigrees of 74 patients with arthrosis, clinically evident, the AA. found evidence of a genetic predisposition to arthrosis.

On a total number of 809 membres, excluding the proband, of these families, they found in 20,8% of them, painful arthrosis, while in 100 families, taken as controll, this percentage is 5,5.

The genetic predisposition to « painful arthrosis » is trasmitted as a dominant character with the parents condition of ge 65,2%), warying according with reduced penetrance (averahaving or not having this disease. There is no avidence, according with the statistical data obtained, of a common genetic ground of predisposition to painful arthrosis and to the two main Rheumatisms (Rheumatic Fever and Rheumatoid Arthritis).

1. For reporting results of calculations of blood group frequencies no more significant figures should be used than are justified by the size of the series tested.

2. Technical and clerical mistakes have been responsible for gross discrepancies in reports on blood group distribution published in the literature, which qualified investigators can recognize by mere inspection of the data.

3. Maximum likelihood calculations are complex and laborious and require a mastery of mathematics which few workers possess. Even in the hands of experts gross errors have resulted when carrying out the laborious computations, so that such calculations are not only expensive but impracticable and dangerous.

4. The application of maximum likelihood calculations by Boyd to two series of individuals tested for the M-N-S types has yielded estimates of gene frequencies differing only in the third decimal place from the values obtained by the author with the aid of simple square root formulae. When one considers, even disregarding the possibility of technical and clerical errors, that the sizes of these two series justified the use of only two significant figures, it is evident that the maximum likelihood method contributed only a dubious increase in „ accuracy ”. Therefore, such calculations consume misdirected energy and place emphasis on superficialities while disregarding more important factors which can affect the accuracy of the data.

5. Many investigators when studying the distribution of the blood groups make the tacit but incorrect assumption that the population is undergoing random mating and is therefore homogeneous. This appears to be one basis for the recent series of fallacious reports on the supposed relationship between the blood groups and various diseases.

6. Confusion in the blood grouping field is due to the fact that most of the articles and books which are published have been written by individuals who have only superficial knowledge and understanding of the subject. The widespread use of the incorrect G-D-E notations reflects the lack of mastery of Rh-Hr serology shared by these workers.

7. It is significant that the same workers who are enthusiastic for maximum likelihood calculations also endorse the pointless studies on blood group distribution in disease, and the use of the superficially attractive but fallacious C-D-E notations.

Examinations of 92 monozygotic and 83 dizygotic twin pairs and 27 families with 78 children have given the result that the ability « tongue curling » is to a certain degree, but not exclusively hereditary. Furthermore, some people are able to learn it. Hence, it is not an unconditionally constant individual trait. By a somewhat more exact functional analysis it is shown that the alternative distribution in the population is counterfeinted only. Hence, there is no evidence for the monomere inheritance lati in Groningen e Drenthe (due supposed by some authors.

By cytological diagnosis of chromosomal sex it has been shown, that about 80 per cent of all cases of gonadal dysgenesis are genetically male. In about 8 per cent of male individuals various defects of red-green sensitivity may be expected. Deuteranopia was observed in a hetero-gametic pseudo-female with testicular dysgenesis. Tests for colour vision should be made in all patients with the syndrome of testicular feminization. From such tests a decision may be expected between sex- linked recessive and autosomal dominant transmission with sex limitation.

While traveling in East Africa, three typical cases of hairy ears were observed incidentally in natives of India, two of whom were from Goa. The inheritance in all three cases was compatible with location of the gene in the Y-chromosome. Two other independent cases have been reported to me from the same general part of India, southeast of Bombay, which indicates a considerable frequency of the gene in this area.

The only previously known pedigree of this condition came from Italy in 1907, and several independent cases in males are described in the early Italian literature. In all these Italian families the hairy ears were associated with insanity or other psychiatric conditions, but this association may have been fortuitous, and hairy ears may be as frequent in Italy as in India.

Two cases are reported of MZ twin pairs with a history of retarded speech and universal stammering followed by concordant agrammatism.

A survey of a number of twin pairs reveals, however, discordance in speech development, in stammering and in language proficiency: agrammatism is, therefore, e genotypical trait.