further than the present state of our knowledge warrants. The group Brachiopoda owes its chief interest to the immense variety and great antiquity of its fossil forms. There are at the present time only about one hundred and twenty extant species. The study of the mollusca occupies 460 pages, the remainder of the work being devoted to the brachiopods. The book is intended apparently as a student's manual. The description is clearly written and contains considerable historical narrative and many good illustrations.
Mr. C odd justifies his Primer of Evolution[1] an abridgment of his Story of Creation, by the reception which the larger work received, and the necessity for putting the material into a condensed and inexpensive form in order to reach the general reader. The first portion is descriptive: matter and motion, from the philosophical standpoint; the distribution of matter and the solar system; and finally two long chapters on the past life history of the earth and present life forms, compose Part I. Part II, the explanatory portion, has chapters on the becoming and growth of the universe, the origin of life and life forms, on the origin of species, and social evolution. The book is written in a popular style, and seems an improvement on its more bulky predecessor.
The high disciplinary value of the study of psychology, which gives a scientific basis to education and lifts it out of empiricism, is distinctly shown in the volume before us.[2] The authors have pointed out, in a very interesting manner, the application of psychology to number. They say that the teacher who knows how the mind works in the construction of number is prepared to help the child to think number. They take the position that the normal activity of the mind in constructing number is highly pleasurable. This is confirmed by actual experience and observation of facts in child-life. There are few children who do not delight in counting, and the fact should be taken advantage of by instructors. A sympathetic and competent teacher can interest them so keenly that apparently wonderful results may be obtained with but little difficulty.
The authors speak of how an absolute distaste for number is created by faulty methods of teaching, with arrested development as a natural result. They say it is perhaps not too much to affirm that nine tenths of those who dislike arithmetic, or who at least feel that they have no aptitude for mathematics, owe this misfortune to wrong teaching at first. The teacher can readily learn from an intelligent study how to make the work of the schoolroom consistent with the method under which by Nature's teaching the child has already secured some development of the number activity. Beginning with a group, counting, parting, and wholing are all in harmony with Nature's method, which "promotes the natural exercise of mental function and leads gradually but with ease and certainty to true ideas of number. It minimizes the difficulty with which multiplication and division have hitherto been attended, and helps the child to recognize in the dreaded terra incognita of fractions a pleasant and familiar land."
The authors' remarks concerning kindergarten work are sound and are based upon results that are evident to all. There is a sure and pleasurable way, along the line of least resistance, that may be followed in the kindergarten, with great improvement in the method of preparation for a child's work later. The authors say: "Surely something is lacking, either in the kindergarten as a preparation for the primary school or in the primary school as a continuation of the kindergarten, when a child after full training in the kindergarten, together with three years' work in the primary school, is considered able to undertake nothing beyond the 'number twenty.'" They add that under rational and pleasurable training of the number instinct in the kindergarten the child ought to be arithmetically strong enough to make immediate acquaintance with the number twenty, and rapidly acquire, if he has not already acquired, a working conception of much larger numbers.
In the easiest possible manner the authors go on to explain every process of number, and the presentation is such as to interest any one impressed with the necessity of a
