have been attacked at an advanced age, and who had consequently resisted a large number of provocative agencies, fewer anomalies are found than among those who were attacked in infancy or youth. If the former held out against a larger number of occasional causes, it was because they were less predisposed, as they were less abnormal.
Teratological abnormities resemble neuropathies not only in their origin and the characteristics of their hereditability, but there can be found in their genesis, besides heredity, all the defective conditions of generation and gestation that have been charged, and justly, with the faculty of giving rise to disorders of the nervous system—emotions, shocks, defective food, alcoholism or any other intoxication, infections, etc. The greater frequency has been noticed of deformities among natural children in cases of conception during intoxication, disproportion in the age of progenitors, etc.
As the masculine sex appears to present a more marked tendency to variation in respect to development and in mental disorders, so it seems to do likewise as regards morphology. Mr. Francis Warner, who has recently examined fifty thousand children in English schools, found 8·27 per cent of physical anomalies among the boys and only 6·78 per cent among the girls. Functional anomalies were also more frequent among the boys.
Like monstrosity, morbid predisposition is the result of a disturbed evolution. In the same way as in families anomalies in form may manifest themselves in very diverse localizations, so anomalies in structure may be variously seated. It is thus comprehensible how, under the influence of the different conditions that usually provoke the manifestations of hereditary diseases—puberty, menopause, fatigue, physical or moral shocks, intoxications, or infections—we observe diverse affections appearing in the same family, but most usually bearing upon the same system. It is worthy of remark that most of these provocative conditions act simply by virtue of the exhaustion that results from them. Growth is usually included among the conditions favorable to the development of disease; but in reality periods of growth, when the processes of nutrition are most energetic, can be and are nothing but periods of resistance; and the susceptibility to attack is developed in the times following periods of growth, particularly of active growth.
The disturbances in evolution of the nervous system are most important in the consideration of the origin of diseases because that system is dominant in the phenomena of the life of nutrition, as well as in those of the life of relation. These disturbances may account for the numerous varieties of morbid manifestations in pathological families.
