expressing the fact that the crude sap which is taken up by the roots needs to be converted into elaborated sap before it may be used as food, she says "When the watery broth is cooked in the sun, the heat of the sun's rays causes the water to pass off through the little leaf mouths. Thus the broth is made fit for plant food." Must not the child possess some scientific knowledge before he will be able to understand the author's meaning? "Plants and her children" is a valuable book, but would not its merits be greatly enhanced if the scientific facts were told in simple language? They certainly have interest enough in themselves to be attractive to the child. Books like Hooker's "Child's book of nature" should be discarded. They represent the old scientific thought. No sympathy or interest in life is aroused, no relationships are suggested, no adaptation to environment is shown, no incentive is given for personal observation. Why should we cling to the old when a book can be obtained that will more nearly satisfy our needs? There is often a great difference in the individual merits of books by the same author. Mabel Osgood Wright's "Birdcraft" is valuable, while "Tommy Anne and the three hearts" and "Wabeno" are the reverse. The last two represent a type of book that should not be included in a science library. The fairy and story element so greatly exceeds the scientific as to render the books absolutely valueless, nor are they a success from a literary standpoint. No book in which the author wanders from one subject to another, in such rapid succession that the reader has difficulty in following the thought, or is so vague that an effort must be made to understand the topic treated, can be of much practical value. The greater number of the Appleton's "Home reading books" possess little merit. The selections were not written for children; they lack simplicity, are not attractive and are too technical. The article "The life of plants" in "Plant world" would require two or three readings by an adult in order to understand what the author was discussing. The best books in this series are Weed's "Insect world" and Holden's "Family of the sun" and "Stories of great astronomers." Such books as Fanny Bergen's "Glimpses at the plant world," Carpenter's "Geographies," Kearton's "Our bird friends," and Weed's "Stories of Insect life" represent the style of book that the elementary science of to-day demands. We do not wish to make scientists of the children, but by means of the best books on nature-study we would prepare the way for elementary science. _Nature-study_ is not _science_, for science is classified knowledge. So far as possible let the elements of personification and fiction be omitted, do not select books that are too technical or vague, that are not well illustrated, and that are not true to science.