Genetische Studien an Zwillingen. A. Morphologischer Teil

Abstract

SUMMARYWe 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 Characteristics1. 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 Characteristics6. Body function as a whole.