The mental diseases are considered under two general heads: (1) Inherited, and (2) Acquired Tendencies. =1. Inherited Tendencies.=—In this class are those cases arising from poor endowment of the protoplasmic structure through lowered vitality of the parents or other progenitors. These taints may come from either parent, or both, and may exist in the offspring from some preceding generation. Such diseases are constitutional and are amenable to supporting treatment in direct proportion to the amount of endowed energy inherent in any given organism. Of the inherited tendencies, we have two kinds: =1. Congenital Diseases.= (a) From any influence of an inherited nature not directly acting on the environment of the parent while the fetus is in utero, and (b) From any influence which directly affects the development of the ovum through imperfect fertilization coming through either parent or both. =2. General Impairment.=—This condition exists (a) Where a similar defect has existed in foregoing generations and is strictly hereditary; (b) Where general vitality is diminished from such causes as neuropathic parents, or where there have existed constitutional defects, such as tuberculosis, syphilis, epilepsy, alcoholism, abuse, overwork, strain, acute inflammatory diseases, and poor health of the mother during gestation; also consanguinity. (c) Premature birth tends to impairment physically and mentally of growth of organism and frequently leaves its manifestations of marasmus, rachitis and other nutritional disturbances. (d) Prolonged labor may leave its mark on the child where more or less asphyxia has occurred resulting in obstruction to cerebral circulation. Causes acting after birth to the already impaired germ cell and resulting in many of the afflictions of early life, both mentally and physically, are 1. Traumatism. 2. Convulsions. 3. Rachitis. 4. Infectious fevers. 5. Meningitis. All of these seriously affect the metabolism within the newly-born, a process which is begun, doubtless with difficulty, and susceptible to easy derangement, and the same effect magnified with growth into its subsequent mental and physical deformity. =2. The Acquired Tendency.=—In this the second great class are those conditions arising subsequent to conception where germ plasm is healthy but growth is arrested by some external factor either intra- or extra-uterine. Thus the acquired tendency may be given to the fetus in utero and not be considered congenital as in case of injury affecting health and growth of otherwise healthy conception. In short, the acquired has its beginning at conception or subsequent to it while the congenital is previous to conception or already inherent in the germ plasm leading to conception. Any influence which retards the 1. Inherent capacity of cell for growth or, 2. Adequate blood supply either in quantity or quality results in enfeebled offspring and these causes are enhanced by