of vivacity, but on approaching the adult period a gradual change sets in. The intellect seems to become clouded, animation giving place to a sort of lethargy, briskness yielding to indolence. We must necessarily infer that the development of the negro and white proceeds on different lines. While with the latter the volume of brain grows with the expansion of the brain pan, in the former the growth of the brain is, on the contrary, arrested by the premature closing of the cranial sutures and laternal pressure of the frontal bone." Since, as Havelock Ellis remarks,[151] even the highest races do not fulfil the promise of evolution they make before puberty, anything which tends still further to impede the fulfilment must be regarded as a factor of degeneracy. Hence intermixture with an inferior race, having an inferior type of pelvis, would tend to degeneracy. CHAPTER VI TOXIC AGENTS The toxic agents which influence the race toward degeneracy, exert that deterioration in a mode which closely resembles that of the degenerative powers of the acute and chronic contagions and infections. The acute poisonings by these toxic agencies resemble the acute, nervous and other exhaustion caused by the toxin of the germs underlying the infections and contagions. The chronic conditions due to these toxic agents agree in many respects with the chronic states produced by the infections and contagions. The toxic agencies are divisible into those belonging to the condiments, medicines, foods and beverages, and those arising from occupations. Tobacco is the most common, while alcohol and opium contend for second place both as to use and as to deleterious effects. Alcohol has been repeatedly charged with being _the_ factor in degeneracy. Statistics of the first half of the present century seem to justify the conclusion that it is apparently the most potent factor, yet these statistics as a rule confound coincidence and cause, or effect and cause, or the vicious circles thereby resulting, to a remarkable degree. There are but few races in which alcohol has not been used and abused. The American Indians[152] had tizwein, chica, and pulque long ere Columbus; the Tartars and Russians, bouza, kvas, and kumyss; the South Sea Islanders ava and toddy (from the cocoanut); the Tunisians, laymi. The vast majority of the races of mankind have used alcoholic beverages. Each was called by a local name and not by a loan word, a most demonstrable evidence of local origin.