THOSE persons whose unhappy lot it is to have much to do with examinations must often feel that there is some fundamental common factor dropped out in the relation between examiner and examinees. A straightforward paper is set in a subject, say A, in which we will suppose there is no attempt to “catch” or perplex the student, but simply to sample, as it were, the ordinary commonplace knowledge which average industry might acquire. There returns to the examiner in due time a mass of manuscript, evidently written with pains and labour, mostly quite seriously meant, but which does not deal with the subject A, but with something which, though apparently related, is evidently quite different, and which we may call A'. After a little while he begins to wonder whether the whole thing is not a nightmare. The form is apparently rational, and yet the details are hopelessly incongruous and absurd. Or, to put the thing in another shape, it is as if one set a paper in solid geometry and got answers from Prof. Sylvester's infinitely thin bookworm.