A group of three cases of Friedreich's ataxia; an isolated case; tabular comparison; remarks on some of the symptoms, ataxia of voluntary movement, static ataxia, Romberg's sign, nystagmus, choreiform jerks, athetoid movements, deformities of upper and lower extremities, and of spine, condition of sensory system, mental state, reflexes, order in which the symptoms appear; their mode of advance; period of onset; increasing complexity of diagnosis; diagnosis of isolated cases; diagnosis from chorea, from hereditary cerebellar ataxia; diagnosis as affected by indications of mental defect; diagnosis from disseminated sclerosis, from locomotor ataxia, especially in children, from cerebellar disease; pathological anatomy; theoretical views as to pathology of the disease; treatment; literature.