In _Every-Day Butterflies_[12] Mr. _Scudder_ relates the story of the very commonest butterflies--"those which every rambler at all observant sees about him at one time or another, inciting his curiosity or pleasing his eye." The sequence of the stories is mainly the order of appearance of the different subjects treated--which the author compares to the flowers in that each kind has its own season for appearing in perfect bloom, both together variegating the landscape in the open season of the year. This order of description is modified occasionally by the substitution of a later appearance for the first, when the butterfly is double or triple brooded. As illustrations are furnished of each butterfly discussed, it is not necessary that the descriptions should be long and minute, hence they are given in brief and general terms. But it must be remembered that the describer is a thorough master of his subject, and also a master in writing the English language, so that nothing will be found lacking in his descriptions. They are literature as well as butterfly history. Of the illustrations, all of which are good, a considerable number are in colors. [12] Every-Day Butterflies. A Group of Biographies. By Samuel Hubbard Scudder. Boston and New York: Houghton, Mifflin & Co. Pp. 386. Price. $2. Dr. _M. E. Gellé's_ _L'Audition et ses Organes_[13] (The Hearing and its Organs) is a full, not over-elaborate treatise on the subject, in which prominence is given to the physiological side. The first part treats of the excitant of the sense of hearing--sonorous vibrations--including the vibrations themselves, the length of the vibratory phenomena, the intensity of sound, range of audition, tone, and timbre of sounds. The second chapter relates to the organs of hearing, both the peripheric organs and the acoustic centers, the anatomy of which is described in detail, with excellent and ample illustrations. The third chapter is devoted to the sensation of hearing under its various aspects--the time required for perception, "hearing in school," the influence of habit and attention, orientation of the sound, bilateral sensations, effects on the nervous centers, etc., hearing of musical sounds, oscillations and aberrations of hearing, auditive memory, obsessions, hallucinations of the ear, and colored audition. [13] L'Audition et ses Organes. By Dr. M. E. Gellé. Paris: Félix Alcan (Bibliothèque Scientifique). Pp. 326. Price, six francs.