The results of the observations referred to by Professor Jastrow are given in Tables of Simple Reaction Times and of Complex Reaction Times. One of the most important points considered is "the overlapping of mental processes," as to which Cattell made a special study. From the fact that the time needed for the performance of complete operations, as multiplying numbers and reciting a verse or two at the same time, is shorter than the sum of the times required to do each separately, it is inferred that the mind should be likened not "to a point at which but a single object can impinge at one time, but rather to a surface of variable extension." Moreover, "the performance of a complex and extended mental task is not the same thing as the separate performance of the several elements into which that task may be analysed." The addition of a classified Bibliography adds much to the value of Professor Jastrow's interesting little work. Ω. ON SAMENESS AND IDENTITY. By _George Stuart Fullerton_. Philadelphia: University of Pennsylvania Press. Mr. Fullerton's psychological study is the first of a series of contributions to Philosophy to be issued by the University of Pennsylvania. It is truly entitled a "contribution to the foundations of a Theory of Knowledge," and is an attempt to arrive at an accurate conclusion as to the several senses in which the word _same_ is used; with an historical and critical statement of the use of the word in a wrong sense. Mr. Fullerton finds that _same_ has seven different meanings according to the mode in which it is applied. In the first case it has the sense of _identity_, and in the second that of _similarity_. Thirdly, the "external" bundle of qualities may be regarded as being the same at two different times, while in a fourth sense, two "external" things, or "external" qualities, existing at one time, may be called the same to mark similarity. Again, an "external" thing or an "external" quality may be called the _same_ with its external representative, as the identification of a thing with its reflection in a mirror. This is the fifth sense; the sixth is where the _same_ "external" object is said to be perceived by different persons. Finally, an "external" thing may be said to be the same "with its representative in consciousness or with the substance or noumenon assumed to underlie it."