pok, pout, pard, bong, cot, tod, of each once; heart, hug, prove, papa, dod, long, tog-each twice; hollow, path, pot, pob, pop, log, pual-each three times; hot, cod, pug-each four times; have, pond-each five; fog, six; park, ten; hard, twenty-five; pog, twenty-six; hod, thirty-six; hog, eighty-five." 1 These tests are very suggestive concerning the teaching of spelling also. A more accurate test is the watch test. The room should be absolutely quiet, and a standard determined by testing several normal persons under the given conditions. The child tested should not see the watch or his imagination will lead to error. The test should be made by gradually bringing the watch toward each ear (the other ear being stopped), and then by slowly removing the watch from the ear. The distance depends much upon the watch and other conditions. The most accurate test known is that made by the use of Seashore's audiometer. This consists of an instrument possessing an induction coil, a dry battery, a galvanometer, a resistance coil, switches, and a telephone receiver, which produce and convey to the ear a definitely graded series of tones. These are controlled by merely adjusting keys which make electrical connections." All cases of deafness found among school children should at once be reported to parents, who in turn should consult a specialist. A large percentage of cases will yield to treatment if discovered in time. All school children ought to be examined about once a year. The tests would not take long to make. If not all are tested the teacher should be on the watch for cases, and those suspected should be thoroughly examined. Causes: Hygienic Suggestions.-There are many causes of deafness, a few of which will be mentioned. First, there are the hereditary predispositions. Fay is authority for the statement that "brothers and sisters of the deaf are found to be deaf in 1 Chrisman, Op. cit., p. 428. 2 Seashore, "Suggestions for Tests on School Children," Educational Review, 22: 69-82. twc hundred and forty-five cases out of one thousand. Where both parents are deaf the children are two hundred and fifty-nine times as likely to be deaf as when both parents are normal." 1 Many children are born deaf in varying degrees from slight dulness of this sense to total deafness. Not a few cases of considerable deafness are undiscovered for months and even years. When there is a hereditary predisposition through scrofulous affections a great many conditions may arise to induce deafness. Chief among these are such childhood diseases as measles, scarlet-fever, whooping-cough, cerebro-spinal-meningitis, diphtheria, mumps, etc. Colds in the head, which are so lightly regarded by many, are apt to develop into chronic conditions of inflammation. The congested membranes may press upon the eustachian tube or prevent sufficient air from entering the middle ear. Reichard claims that of all causes of defective hearing this heads the list. All catarrhal diseases producing hypertrophied conditions of the nose and throat cause multitudes of cases of disturbed hearing. Adenoid growths often result, which press upon the eustachian tube, fill the nasal passages, or otherwise obstruct the breathing. The mouth-breather should always be examined carefully, as conditions quite likely exist which demand immediate attention. Enlarged tonsils are a frequent cause of deafness. Adenoids and enlarged tonsils usually accompany each other. They are of surprising frequency. One physician informed me that he had operated upon one thousand two hundred cases in eight years. How many more must have been suffering from the same causes! It is of vast importance to have the specialist remove these growths, thus usually relieving the deafness. If attended to before adolescence the cure is usually complete. If postponed until later, for some unknown reason, cures are much less frequent. If present in infancy, adenoids sometimes develop such alarming proportions as to press upon the brain and produce idiocy. Undoubtedly many children might have been saved to society had they received the attention of the specialist early enough. 1 CHAPTER XII INDIVIDUAL VARIATIONS AND DIFFERENCES General Considerations.-There are few who would not admit that among people there are many obvious differences of physical structure, and that these differences are natural. But when mental qualities are considered it is at once assumed that all are alike or would be if educated alike. Teachers even are apt to think that all the intellectual differences among children can be accounted for by differences of diligence, willingness to work, application, etc. They will even admit temperamental differences to account for differences of application, but tacitly assume that intellectually "all men are created equal." No greater fallacy ever existed. No two individuals were ever exactly alike, physically, mentally, or morally. Occasionally a pair of twins seem almost indistinguishable, but careful study of them always reveals large differences. The organic world reveals great differences among individuals of the same species. In the plant world it would be impossible to find two leaves, two blades of grass, or two plants absolutely alike. Some slight differences serve to give each its individuality. In turning to human beings we shall not find it difficult to discover abundant cases of individual variations. There are the giants and the dwarfs, the tall and the short, the blondes and brunettes, beautiful and ugly, black and white, good and bad, choleric and phlegmatic, brilliant and stupid, blue-eyed and brown-eyed, and other extremes too numerous to chronicle. Between these extremes there are all grades and shades of apparent difference. Besides these obvious differences there are innumerable variations which are not so apparent and hence thought not to exist. Some persons burst forth into song with the most meagre training, while others, with the best masters, could never carry a tune or discover discord; some are ready spellers, while many others are hopeless; some are born mathematicians, while others never can progress beyond the merest rudiments. One child early exhibits mechanical genius, devising appliances for every sort of work, while another can never learn to put together the simplest contrivance; one can memorize verbatim with the greatest ease, while another can never repeat a quotation; one person picks up the pen and without training begins to produce literature, while another cannot chronicle accurately the simplest event; one mounts the platform and charms the multitude with his eloquence, while another is made mute in the presence of an audience. Although all human beings possess the same general faculties, yet there are wonderful differences of development among individuals and also between the lowest and the highest as a class. Even zoologically there are notable developmental differences. Fiske remarks that: "The cranial capacity of the European exceeds that of the Australian by forty cubic inches, or nearly four times as much as that by which the Australian exceeds the gorilla; and the expansion is almost entirely in the upper and anterior portions." Anatomical Variations.-Anatomists inform us that there is great variability in all parts of man's structure. Many organs are atavistic in nature and approximate the structures of other animals. The arteries are so variable that surgeons have found it necessary to determine the probable proportion of each variation. The point of decussation of the brachial artery sometimes varies five or six inches. Occasionally the branching takes place at so high a level as to make the artery appear double. The position of the heart varies so much that in occasional cases it is transposed from the left to the right side of the body. This condition is usually associated with a general transposition of the viscera and the possession of a right instead of a left aortic arch. The internal structure of the heart varies greatly 1 1 among individuals. An occasional person has all double teeth, others have double rows of teeth. Wallace reports that muscles are so variable that in fifty cases studied no two were alike. In thirty-six cases no fewer than five hundred and fifty-eight variations were found. In a single male subject seven muscular variations atavistic in character were observed. "Autopsies have shown that in right-handed persons the speech centre is placed or is functional usually in the left cerebral hemisphere, while in the case of left-handed individuals aphasia and paralysis are produced by lesions involving the right side of the brain." Wiedersheim is authority for the statement that there are such great individual differences of development of the muscular system that new muscles, not catalogued in the text-books, can be found in nearly every person. These variations are retrogressive and vestigial, occasional, or atavistic; and progressive or newly developing structures. Donaldson tells us that among brains, as in the case of all organs called similar, there are very numerous and wide variations. The statistics on the brain. weights of eminent men and the discussion of the relation between body and mind show this very clearly. Thackeray's brain, weighing 1,644 grams, is the heaviest recorded; while Tiedemann, the great anatomist, equally as great in intellect, possessed a brain weighing only 1,254 grams. Not only are there great variations in size and weight, but also in structure. In measuring height sitting and standing, "Zeissing found individual differences here so great that the proportions of some children at four were like those of others at fourteen." The finger prints of each person are so unique in character that they are as certain a means of identification as a photograph. This method is so accurate that it has been used to some extent in identifying and in tracing criminals. It has also been used in banks as a means of identifying depositors, being much more conclusive than 5 1See Cunningham's Text-Book of Anatomy, pp. 946–956, for many interesting cases of variations. 2 Darwinism, p. 447. 3 Howell, Text-Book of Physiology, p. 216. 4 Growth of the Brain, p. 134. 'Hall, Adolescence, I, p. 61. |