ally occur. It is not less essential to know these points of failure than to know the foundations of knowledge which the pupil has already mastered. For these weak spots must be remedied as we go along if the later work is to be successful. Very frequently classes are unable to proceed satisfactorily because of lack of thoroughness in the foundation work which precedes. To know where a pupil is failing is the first requisite if we are to help him remedy his weakness.
But not only must the teacher know where the pupil is failing, but also the cause of his failure. Only when we know this can we intelligently apply the remedy for the failure. A physician friend of mine tells me that almost any quack can prescribe successfully for sickness if he has an expert at hand to diagnose the case and tell him what is the matter. This is the hardest part of a physician's work and requires the most skill. So it is with the teacher's work as well. If we are sure that a certain boy is failing in his recitations because