=Induced Immunity Not Inherited.--=Lastly, it is well known that various animals, including man, after recovery from an attack of any one of certain diseases, become more or less immune from further attacks of the same disease. Moreover in some instances as in inoculation against typhoid or diphtheria, immunity may be artificially induced by means of anti-toxins. The question arises as to whether such immunity is transmitted to offspring. Experiments have been made (see _Bulletin No. 30, U. S. Hygienic Laboratory_) to test this and it has been found that the condition is not inherited. Young guinea-pigs, for instance, born of mothers immunized during pregnancy are immune at birth but they lose their immunity in the course of a few weeks. The effect is clearly one of direct transference from the blood of the mother. The same temporary immunity can be produced in the young, in fact, by merely having them nurse from an immunized mother. =Non-Inheritance of Parental Modifications Has Social, Ethical and Educational Significance.--=Like many other biological conclusions these relative to the non-inheritance of parental modifications are of extreme importance to humanity. It is clear that they have not only physical but social, ethical and educational significance. For if the education which we give our children of to-day, or the desirable moral conduct which we inculcate does not affect the offspring of succeeding generations through inheritance, then the actual progress of the race is much slower than is commonly supposed, and the advance of modern over ancient times lies more in an improvement in extraneous conditions through invention and the accumulation and rendering accessible of knowledge, than in an actual innate individual superiority. And when we face the issue squarely we have to admit that there is no more indication of the inheritance of parentally acquired characters as regards customs, knowledge, habits and moral traditions than there is of physical features. In fact, if such acquirements were inherited then we should soon have a race which would naturally, spontaneously as it were, do what its ancestors did with effort. Yet we do not find the children in our schools reading, doing sums and developing proper social relations without ceaseless prompting and urging on the part of the teacher. Indeed I can testify that this necessity carries over even into a university. In short, the habits and standards of each generation have to be instilled into the succeeding generation.