The Authors have studied the blood iron level in 94 twins (23 MZ and 24 DZ pairs) aged from 6 to 14 years.

Through the determination of the blood iron level a mean value of 45,59 mgs per 100 cc. of blood has been established. This value corresponds to that of single-born children of the same age; thus, the anemia ferri priva observed by Woodruff in twins during the first year of age may not apply to ensuing ages.

The comparison of the blood iron level at the ages taken into consideration has shown a slights progressive lowering of the blood iron, which the Authors consider physiological. The comparison of the blood iron level between MZ and DZ twin-pairs has not revealed a significantly different behavior. The twin test appears thus to demonstrate that the blood iron level is not genotypically determined, but is environment-conditioned, generally through thermic and gaseous exchanges between the organism and the environment in which it lives.

The Authors have studied a pair of MZ twins, both affected with ocular albinism, two boys—probably consanguineous—also affected with ocular albinism, a DZ opposite—sexed twin—pair with the male twin affected with ocular albinism and many relatives affected with localized or generalized pigment anomalies, and the female MZ twin-pair concordant as to total albinism, already described by Hanhart.

The Autors criticise current classifications of hereditary albinism which do not accord themselves with the samples and which do not explain the phenogenesis of the disease. They suggest to classify the hereditary forms of albinism in two fundamental classes. In the first one would be included the cases of total and non-total albinism depending on an enzymopathy which alters the normal melanogenesis. In the second one would be included the cases in which the specific enzymes, tough normally present, encounter some local causes enhibiting their action. Cases nos. I and II of the present work would belong to the first class, while cases nos. III and IV would belong to the second one.

The Authors show that the mitostatic action of hydrazine, ascertained on higher plants—is also present in the cells of Erlich's tumor-ascites in rats. Through the association of colchicine with hydrazine a metaphase-block is obtained, in which the number of affected cells as well as the ensuing cellular pathology are remarkably cleac. The Authors stress out the usefulness of the above association in mitotic pathology and its great possibilies in the field of the cytostatic therapy of leucoses and tumors.

Genetically determined abnormalities of structure or function occur either single or in various combinations. As genetic syndromes should be designated only those combinations that are typical, that is, significantly more frequent than would be expected from pure chance association. Some genetic defects are part of a syndrome or they only accompany other syndromes as irregular trimmings in various distribution and frequency. The accumulation of such “degenerative stigmas” as they were known to clinicians of an older generation had been called “status degenerativi” or “polygenopathy” and attributed to a “mess in the chromosomes” by the author long before this concept has been substantiated by the newest discoveries of British investigators. The biologic significance of such polygenopathies as to adaptation, resistance and general viability of their carriers has been stressed and a more satisfactory terminology suggested.

The dermatoglyphics of 100 mongol patients from Switzerland were investigated. The results are as follows:

1. Worls and arches are more scarce than in normal persons of the European races: 23.7% whorls, 1.0%. arches.

2. The very numerous loops (75.3% are frequently steep and narrow, the ridges tender or dissolved into pearls. Strong ridges often seem to be dismembered.

3. The ridges of the hands in the distal region want of swing and appear tightly stretched. The main line index (Cummins) reaches 10.15, the highest value so far found.

4. The patterns in the balls of the hands are much more numerous than in normal Europeans. The hypothenar pattern is sometimes extremely extended.

5. The axial triradius t”, rare in normal persons, is manifested in 80.0%.

6. The three and five-finger furrows are in nearly 60.0% changed and form more or less clear a four-finger or ape-furrow.

7. In spite of the distinctness of these characters it is not advisable to found the diagnosis of mongolism on them alone; clinical characters are necessary at all events.

6 pictures represent the various forms.

The Authors study the distribution of the various classes of Arneth's formula in 39 healthy MZ pairs, 38 healthy DZ pairs, 10 MZ pairs with non-concordant disease.

They conclude that borh genetic and pathologic factors are relevant in the determination of the formula, and they will try to establish the importance of each factor through a further study on a group of DZ pairs with non-concordant disease.

After having examined the literature on the subject, the A. presents the study he has carried on 60 twin-pairs with one or both twins suffering from neurosis or psychosis.

In 50 pairs a psychic suffering of neurotic type was present: out of the 20 MZ pairs, 18 were concordant with a percentage of 90%; out the 30 DZ pairs, 13 were concordant 43%.

Although discriminating the various forms and admitting the interference of environmental factors and other somato-psychic and psychogenetic causes, in 50% of the cases an undoubted psychotic and neurotic heredity was ascertained.

In the four pairs suffering from dysthymic psychosis the 3 MZ were concordant and the DZ discordant.

In the four pairs suffering from schizophrenia the MZ pair was concordant while the 3 DZ pairs were discordant.

In the two pairs of uncertain zygosity the concordance could not be extimated due to the death of the cotwin.

Dysthymia seems to be trasmitted as a dominant character and schizophrenia as a recessive.

Both dystymia and schizophrenia may undergo changes of expressivity with phenotypical characters which can be clinically mistaken as psychoneurotic forms.