The cretin is a feeble-minded person whose condition results from the absence of or hyper trophy of the thyroid gland, the consequence of which is an arrest of development both phys ical and mental. The cretin is of small stature and of low mentality. If, however, the conch tion is discovered in infancy, the child may be fed the thyroid gland of sheep or other animal and develop almost if not quite normally.
The Mongolian type is so called because of its more or less marked resemblance to the Asiatic races, the slanting eyes and general ap pearance of the face. In addition to this the condition is characterized by short, stubby fin gers, absence of the occipital protrusion, show ing a straight line from the neck up, and fre quently, although not always, a deeply fur rowed tongue. They generally have very poor circulation and suffer more or less from affec tions of the eye. They are exceptionally af fectionate. The cause of the condition is not known, but it is something that acts in utero and probably affects the nutrition of the mother. For other types and other details the reader is referred to the works by Tredgold, Barr, Shuttleworth and Potts (see The present movement for the care of the feeble-minded was begun in 1837 when Dr. Seguin, called the apostle of the idiot, began his work in Paris. Some sporadic at tempts had been made before this but they were of short duration and amounted to but little. In 1811 Napoleon ordered a census which showed over 3,000 cretins in one canton in Switzerland. In 1816 a school was founded for cretins at Saltzburg, Austria. A few idiots were trained at the asylum for the deaf and dumb at Hartford, Conn., about the year 1820.
The first institution for idiots was estab lished in Germany in 1835. In 1841 another institution for cretins was founded by Dr. Guggenbuhl on the Abendberg, near Interlaken in Switzerland. This institution lasted 20 years.
In 1848, Dr. Samuel G. Howe started a class for the training of idiots at the Blind Asylum in South Boston, Mass. This led to the found ing of the Massachusetts school, in 1851, for the care and training of the feeble-minded. New York established a similar school at Syra cuse, N. Y., at about the same time. From that beginning the work has grown in the United States until at present there are one or more State institutions for the feeble-minded in 34 States.
These institutions are caring for approxi mately 35,000 feeble-minded and epileptic per sons, constituting about one-tenth of the esti mated number of feeble-minded in the United States. (For further details consult Fernald,
W. E., The Growth of Provision for the Feeble-minded in the United States').
In the Vineland study of 300 families Goddard found 66 per cent of feeble mindedness hereditary, that is, the cause is defective germ plasm, which is transmitted probably in accordance with the Mendelian law of heredity. Of the remainder about 12 per cent appear to be due to what is called neuro pathic ancestry. That is to say, the families are characterized by the presence of neuropathic conditions such as paralysis, hemiplegias, insan ity, alcoholism and the hire. Nineteen per cent are classified as being due to 'accidental* causes including certain diseases. Of the lat ter, cerebrospinal meningitis is the most im portant, although typhoid fever, measles and even whooping cough are supposed by some to cause the condition, though this is doubtful. In 2.6 per cent of the cases no cause could be found. Alcoholism and syphilis are popularly supposed to be potent causes of this condition, but the evidence is inconclusive, since such cases often show also a family taint of feeble mindedness, or neuropathic or other conditions that may equally well be causes. The further fact that there are large numbers of alcoholic and syphilitic families who do not have feeble minded children throws doubt upon the prob ability of these conditions being causes.
Diagnosis.— The condition is now usually diagnosed by the aid of mental tests. A system of mental tests called °A. Measuring Scale for Intelligence' was first devised by Drs. Alfred Binet and Th. Simon of Paris. This has since become widely has been revised and ex tended and is the stimulus and guide for many other systems of tests.
Scientific Study.—The first systematic scientific study of the condition and the causes of feeble-mindedness seems to have been made under the direction of Dr. Arthur C. Rogers at Faribault, Minn. Dr. Rogers opened a laboratory in 1898 and employed Dr. A. R. T. Wylie as This work was dis continued in 1902. Superintendent E. R. John stone organized a laboratory at the training school for the feeble-minded at Vineland, N. J., 15 Sept. 1906. This work has continued and grown until the laboratory now occupies an entire building with a number of workers. There are also laboratories at Faribault, Minn., Waverley, Mass., Lincoln, Ill., and Eldridge, Cal.