These conditions occur from heredity in degenerates, but, as Francis Warner[185] remarks, while "it is very common to see disordered conditions of the nervous system in children with defective construction of body, these nerve disturbances may also be seen in children with normal construction of body. Such signs result from the disorder, produced by special circumstances, aiding as well as producing defect which results from, or in the next generation becomes, defect in original construction. Among the signs of fatigue in children is the slight amount of force expended in movement, often with asymmetry of balance in the body. The fatigued centres may be unequally exhausted; spontaneous finger twitches like those of younger children may be seen, and slight movements may be excited by noises. The head is often held on one side. The arms when extended are not held horizontally. Usually the left is lower. The face is no evidence of bodily nutrition. It may be well nourished, yet the body be thin. Three per cent. of the children seen in school are below par in nutrition. These children are of lower general constitutional power. They tend to an ill-nourished condition under the stress of life, and many cases of mental excitement which, while they render them sharper mentally, militate against general nutrition." Colin A. Scott has found corroborative evidences of similar effects of strain in the children of the New England and Illinois schools. These systemic nervous exhaustions may, as W. S. Christopher, of Chicago, has shown (in remarks on neuroses already cited), take unexpected local directions, especially involving, in accordance with the general law of reversal, evolution or degeneracy checks on excessive action. Among the conditions produced by school strain of serious consequence in after-life are headaches, usually charged to anæmia or neurasthenia. These headaches, as Sachs,[186] of New York, has shown, usually appear after emotional excitement or fatiguing ordeal. There are other symptoms expressive of neurasthenia, such as slight tremor of the tongue and fingers and exaggeration of the deep reflexes, but, above all, the very persistent vertex headache, and the child's description of pressure or heat there. In children emotional conditions, school strain, rivalry between class-mates, are as liable to produce neurasthenia as are the more serious struggles for existence in later life. These headaches may pass very readily at periods of stress into migraine. The vertigo characteristic of migraine is not rarely found in the neurasthenic headache of childhood. What is true of migraine is also true of epilepsy. The tremors, &c., accompanying neurasthenic headache become the convulsions of epilepsy. G. B. Fowler reports a case emphasising very clearly the position of Christopher. It was that of a seven-year-old boy of mushroom growth and hothouse culture. He began every day before breakfast with an hour at Spanish, and until