with which each pattern type occurred amongst different peoples. His classification of fingerprint patterns was considerably more simple than that proposed by Purkinje, delineating only three main types of pattern. He identified the triradius as being the significant indicator of a fingerprint pattern type and hence based his classification on the number of triradii to be found within each pattern.

However, Galton is perhaps the single most influential figure in the whole study of the skin ridge patterns of the hands and many of his methods for analysing fingerprints have carried through into the work of later genetic dermatoglyphic researches. His interest in heredity focused on the possibility of raising the standards of physical and mental health amongst the population as a whole and he saw in the study of fingerprints a means to initiate investigations into human genetics with this aim in mind. To this end, in 1895 he established the Galton Laboratory for Eugenics (a term he himself coined in 1883), at the University of London, which was later to conduct extensive investigations into the genetic significance of the hand as well as investigating correlations between dermatoglyphic patterns and known chromosomal abnormalities. His two works 'Fingerprints' (1892) and 'Fingerprint Directories' (1895) are rightly considered as classics in the field of early dermatoglyphic research and stimulated the interest of all sorts of scientific investigators,such as anthropologists and zoologists as well as geneticists and criminologists.

The Genetics of Dermal Ridges

After Galton's initial pioneering work, many further investigations were undertaken to develop this fledgling science of dermatoglyphics. Anthropologists concentrated on researching dermatoglyphic distributions of different peoples from around the world, and work was done on clarifying both the methodology and morphology of dermatoglyphic analysis. Meanwhile, the scientific world pioneered studies to investigate the embryogenesis of dermatoglyphic patterns and the first studies investigating the genetic significance of dermatoglyphic patterns were conducted. In America, HH Wilder inaugerated investigations into comparative dermatoglyphics, producing work on both the methodology and morphology of both palmar and plantar (feet) dermatoglyphics. H Poll and J Dankmeijer instigated research into dermatoglyphic distributions amongst different races and K Bonnevie investigated the embryology of dermatoglyphics as well as conducting studies on the genetic inheritance of dermatoglyphic patterns. The scientific investigation of the hand was beginning to prove without doubt that the hand was indeed a study worthy of the finest minds and could reveal not only vital genetic and medical information about an individual but also something of the psychological uniqueness of each person. With the discovery of the significance of dermatoglyphics, the study of the hand was truly beginning to come of age.

Fingerprints, Palms and Soles

From the mid 1930's onwards, the hand was coming to be recognised as an important diagnostic aid in the diagnosis of congenital syndromes such as mongolism. LS Penrose had studied the hands of people with Down's Syndrome and other conditions of congenital mental defect for many years and had discovered that the hand revealed particular malformations peculiar to these conditions. In 1931, he penned an article for The Lancet correlating the absence of the medial digital crease on the little finger with congenital mental retardation, research that proved to be but the start of a long and detailed investigation into the relevance of the hand in the clinical diagnosis of congenital conditions. However, the main breakthrough in establishing the significance of the dermatoglyphic analysis of the hand came with the publication of the results of the research of Harold Cummins and Charles Midlo in their seminal work 'Fingerprints Palms and Soles' in 1943.

When it was later discovered that Down's Syndrome was in fact caused by chromosomal abnormality, research was begun to see how far the hand could be used as a guide to diagnosing other chromosomal defects and dermatoglyphic analysis soon became referred to as 'the poor man's karyotype'. The researches of Cummins and Midlo had proved that the hand could be of particular significance in the study of diseases with a genetic origin and, given the expense involved in conducting analyses of the chromosomes themselves, dermatoglyphic analysis was now beginning to prove itself as an extremely useful tool for preliminary investigations into conditions with a suspected genetic basis.

Genetic and Chromosomal Research

It was reading Cummins and Midlo's work that inspired LS Penrose to conduct his own dermatoglyphic investigations as a further aspect of his research into Down's Syndrome and other congenital medical disorders. In 1945, he was appointed to the Galton Chair of Eugenics at London University. Although the post had existed for some fifty years up to this point, very little research had actually been done into the genetic significance of fingerprints. Penrose was about to change all of that. Whilst he held the post, he conducted extensive investigations into chromosomal disorders and their dermatoglyphic manifestations, considering not only the more common trisomies such as Down's Syndrome, Edwards Syndrome and Patau's Syndrome, but also initiating investigations into other more rare chromosomal disorders such as 'Cri du Chat' Syndrome, and the sex chromosome disorders, Turner's Syndrome and Kleinefelter's Syndrome.

Characteristic Palmar Features in Down's Syndrome