The Author reports two MZ twin pairs, one of 11 years old females and one of 18 years old males, only one twin in each pair being affected by severe cardiac failure. In both cases the cranial radiograph of the hyposystolic twin, compared with that of the co-twin, revealed the existence of cereblar stasis.

The Author also reports on two female MZ pairs of developmental age, each with one cardiopathic twin. In both cases the affected twin revealed a retarded body development and, in one pair, also retarded puberty.

The Author stresses how the twin study method is helpful in clinical as well as genetical research, thus reasserting its validity.

The Authors have studied radiographically the thorax of 11 pairs of uniovular twins and of 16 pairs of binovular twins. They have performed and analyzed the standard radiographics of the thorax as well as four transverse laminagrams. The results show a greater concordance of the cardio-vascular shadow and that of the pulmonary hili in the uniovular twins. This concordance is more marked and demonstrative in the transverse laminagrams than in the standard radiography. The Authors think that this finding is due to a lower incidence of the functional variants in transverse laminagrams. Moreover, they have given the name of lingua pectoralis to a peculiar radiographic image of the anterior mediastinus.

In a previous work the Authors have reported that the so-called «Klippel-Feil Syndrome» should in many cases be ascribed to a hereditary disease of the axial skeleton. This disease can express itself in various degrees (macroforms or microforms) fundamentally identified by fissure and synostosis: the Authors suggested that the disease might be identified as «schisosynostosis axialis congenita familiaris».

In the present work the Authors report the case of a twin suffering from congenital osseous torticollis, whose co-twin, apparently healthy, was found instead to be affected by posterior synostosis of C2 and C3 and by fissure of S1 and S2, as well as bv sacralization of L5 and traces of cervical platyspondyly.

In the same family the father was found to suffer from basal segmentation of the dens epistrophei, by cervical kyphosis and fissure of S1; a brother was affected by synostosis of the laminae of C2 and C3.

In the discussion of the case the Authors come to the conclusion that congenital osseous torticollis can be ascribed (as was the case with Klippel-Feil's Syndrome) to «schisosynostosis axialis congenita familiaris» of which it represents another possible anatomo-clinical expression.

This study is based on pedigrees of 479 patients with Primary Rheumatism (287 patients with Rheumatic Fever and 192 with Rheumatoid Arthritis) which are compared with pedigrees of 300 controls. The conclusion of this study is that the predisposition to Rheumatic Fever and to Rheumatoid Arthritis is trasmitted by a single principal autosomal gene wich is dominant and has reduced penetrance and variable expressivity.

The appearance of the acute and the chronic forms of the disease is in function of accessory modifying factors, as genetic and acquired ones. These factors condition the variation of the organic reactive response into the ambit of «type of reactivity» trasmitted by the principal factor. The possible existence of accessory modifying factors, admitted because the way of appearance of the disease in the various generations of families, it occurs in similar situations of human and experimental genetics.

The predisposition to primary rheumatic disease has no genetic relationship to the diathesis of allergic diseases and the diathesis of degenerative connective tissue disorders (mesenchymotic diathesis).

The Authors have studied the influence of angle televisive spectacle on both angle and amplitude of visual fusion in 50 twins. Television appeared to produce an increase of the simultaneous macular perception and a marked change of fusional convergence and amplitude. Furthermore, it increases the fatigability of individual convergence.

The twins method, employed by the Authors, has demonstrated that the televisive effect acts on a hereditary background, involving also hereditary mechanisms.

Roentgenograms have been taken of the hand and wrist on 58 pairs of MZ twins, on 40 pairs of DZ twins, and on 4 groups of triplets, between 2 and 18 years of age.

Their comparative examination has shown the highest concordance in MZ pairs and a remarkable discordance in DZ pairs, accentuated above all in those of opposed sex. Generally, the comparison between male and female pairs of same age has shown a delay on bony growth of the firsts, event remarkable also within DZ pairs of opposed sex.

Comparing the Roentgenograms taken with those standard of Greulich and Pyle, generally it is to be remarked that males are retarded in regard to females.

Some cases of concordant paramorphysms in healthy pairs of MZ twins and of remarkable immaturity in MZ pairs at the same time sick are also shown.

Report about the many possibilities of pathological dwarfism. It is not too much if we suppose, that more than 100 different gens may cause special forms of pathological dwarfism in man.

The Autors analize 25 families with proband affected by thromboangiitis obliterans, 25 families with proband with periferal arteriosclerosis obliterans and 300 families with proband with infectious diseases. The last two groups are as controll.

After describing two cases of thromboangiitis obliterans on the families of proband with T. O., the AA. examine the material under the statistical point of view.

In the group of families with T. O. they founf on higher incidence statistically signifiant, of rheumatic diseases (rheumatic fever and rheumatoid arthritis) and cerebral apoplexy of early unset (before 55 years of age).

The AA. admitt the existence of a genetic predisposition to thromboangiitis obliterans.

Such a predisposition probably leads on two genetic factors: one dominant autosomal with reduced penetrance and variable expressivity, witch is responsable of the abnormal mesenchimal reactivity (and for sue a reason, strictly related to the principal factor responsable of the predisposition to rheumatic disease). Tre other, recessive one, is responsable of a state of vascular vulnerability. This last factor is probably the localizing factor of the abnormal responsivity to the vascular mesenchima.

The genetic predisposition to rheumatic diseases, in the other way seems to have non genetic relationship to the diathesis of allergic diseases and the diathesis of degenerative connective tissue disorders (mesenchymotic diathesis).

Data on congenital total color-blindness were collected from the Japanese literature and through private communication, and tested for partial sex-linkage. Twenty sibships derived from consanguineous marriages, in which mode of relationship of the parents was fully known, were analyzed by using the direct method, and the crossover values 37.9-39.0% were found. Remaining 26 complete sibships were analyzed by using the indirect method, and a crossover value of 23.7% was obtained.

The higher recombination value derived from the direct method may possibly due to inaccurate information about paternal genotypes.

We have studied, in this work, environmental variability in twins, including the influence of age on the morphological and functional, physical and psychical characteristics.

I. Morphological Characteristics

1. For anthropometric measurements, most of the measurements of the cranium and of body lenght reveal a relatively high similarity between MZ twins, i. e. a high hereditary conditioning and low environmental influence. Most measurements of body volume and weight indicate instead a wider percentile intra-pair difference in MZ twins, indicating higher environmental susceptibility. Among constitutional indexes, Pignet-Vervaecksche's index appears to undergo the highest hereditary conditioning.

2. The heart, the first section of the aorta, the lungs, thorax and stomach were examined radioscopically. Their shapes appeared largely conditioned by heredity. Their measurements (obtained by telefilms) are, in part, conditioned by heredity.

3. The vessels of the retina and the capillaries of the skin are also conditioned by heredity.

4. Finger and palm ridges clearly show similarity in MZ twins. Examining MZ twins belonging to different age groups we have found that similarity of finger ridges was higher in MZs between 6 and 8 years of age than in later age groups.

5. As for blood cells, their size is largely conditioned by heredity, but also highly susceptible to environmental influences. The Hemogram and the Elmonogram of the leucocytes are, to a certain degree, conditioned by heredity. No clear appraisal could be made of the influence of heredity on the blood platelets count and on the reticulocytes.

II. Functional Characteristics

6. Body function as a whole.

A mathematical model is described, covering the case of paired recessive diallelomorphs with different degree of penetrance in the pairlings, according to whether the proband carries 1) the trait, 2) the genotype but not the trait, 3) neither the genotype nor the trait. The incidences of trait-carrying pairlings in the three proband groups are expressed in terms of population genetics and formulae given, together with some conclusions.

The history of the development of knowledge of the Rh-Hr types is briefly reviewed, with special reference to the theory of multiple allelic genes. It is pointed out that this theory has been confirmed by numerous statistical studies of the Rh-Hr types in the population as well as extensive studies on families. In addition to corroborating the genetic theory, the newer studies have disclosed the great complexity of this blood group system, so that as many as 20 allelic genes have been identified up to the present time. In the case of the more common genes there is ample direct evidence to verify the genetic theory, but observations on the rarer blood types are necessarily limited, so that the validity of the genetic theory, as it pertains to the rarer Rh genes, is based mainly on analogy. In this paper, two unusual families are recorded, which illustrate the hereditary transmission of the rare agglutinogens rh′w and Rhz. These observations serve to justify the inference that the rarer Rh genes are subject to the same laws of heredity as the more common alleles of the Rh-Hr allelic series.

The Author studies the relations between the physical and psychical resemblances in two groups of similar (18 pairs) and dissimilar (21 pairs) twins.

The physical characters considered are: the measurements and indexes of the head, face and nose.

The psychical characters are: attention, auditive memory, visual memory, taste for colours and mental level.

The similar twins betray great resemblance with regard to the measurements and indexes of the head and face and very notable differences with those of the dissimilar twins (excepting the measurements and indexes of the nose).

With regard to the psychical characters studied, many (visual memory, taste for colours, mental level, concordance in mistakes) do not show any notable differences. The auditive memory (weak) and the index of attention (very high) betray, however, notable differences. No correlation is observed between physical resemblance (given in millimetres) and concordance in mistakes; while the relation is strong between physical resemblance and the index of attention.

The simultaneous occurrence of sarcoidosis in two 24yearold white men who where enzygotic twins is reported. Manifestations of the disease as well as its clinical course were identical in both twins.

A study of 30 families, belonging to a 290 individuals pedigree, showes that the epithelioma adenoides cysticum is genetically influenced by an autosamal dominant factor. But, owing to penetrance differences between sexes, apparently the disease is irregularly transmitted.

The Authors refer the results of the genetical research on 91 probands with cancer of the corpus uteri (unselected sample of the 144 collected cases). In comparison with a suitable control material significant higher familial incidences result in females for uterine cancers and in males and females together for cancers of all sites.

The object of this study was to ascertain if endogenous factors might play a part in the appearance of paralysis with acuta anterior poliomyelitis.

The investigation concerned 754 patients in Groningen and Drenthe (provinces of the Netherlands), affected by the disease during the years 1936-1951. First of all it appeared that the consanguinity percentage of the parents of the probandi was much higher than that of the average population the difference being significant (χ2 = 22,28; P: 〈0.001). Secondly we compared the number of connections of a group of 137 patients with a group of 591 patients and the number of connections of a control group of 137 persons with the group of 591 patients. As ignificant difference appeared to exist between the numbers observed. The third part of the research concerned the appearence of diseases with patients' relatives and the comparison of those with the diseases with relatives of a control group. Between the group of patients and relatives and the group of control cases and relatives a difference appeared to exist in this sense that in each case the group first-mentioned showed a “surplus” of diseases in comparision with the control group; the burdening of the poliomyelitis-group with these diseases showed a significant difference from that of the control group. Also in this case the comparison of several separate diseases showed significant differences. However this was not the case with all the diseases. Attention was paid to the twins who occurred in the group of 754 patients. The small number of twins, however, did not allow of any conclusion whatsoever.

Finally the conclusion has been drawn, that endogenous factors exercise influence in the origin of paralysis with acute anterior poliomyelitis. The results of this investigation render it probable that we have to deal with a non-specific factor, viz. a greater vulnerability of the central nervous system for diverse diseases of which the increased susceptibility of the paralytic form of acute anterior poliomyelitis forms a part.

This factor is inherited in a recessive way.

The Author sets out his standpoint on the value concerning the « forme fruste » of syndromes of multiple malformations expecially of those which have hereditary nature. He remembers the four types of « mandibulo - facial dysostosis ». The Author describes a family in which the different members were affected by this illness in incomplete form. In the last generation by two parents having the « forma frusta », two children were born, affected by a complete Mandibulo - facial Dysostosis both after having lived two or three months. After a close examination of medical literature referring the familiar forms, man examine all the genetical eventuality concerning the examined family. Man can reach to a conclusion that the appearence of two brothers with a complete forme, precociously dead, is quite surely imputable to « homozygotism » and consequently to double close of « pathological genes ».

The authors describe a new hereditary dystrophy of the cornea, the specked heredo-dystrophy of the corneal parenchyma. In the corneal stroma of both eyes speckles can be easily distinguished; they are more or less numerous and can be found in all the layers of the parenchyma, as well in the center as at the periphery. Dimension, shape and density of the speckles are very variable: they are oval, round or festooned; some of them are opaque at the borders; others show a more diffuse trouble; others are dotted; their borders are well-cut, regular or indented. In optical section the opacities are thin and flat. This dystrophy is not evolutive and is transmitted as an autosomal regular dominant trait. One member of the affected family shows a cloudy central dystrophy of the corneal stroma, so that it is possible that there exists a relationship between these two affections.