This sounds like a most formidable and delicate task in the _judicious employment_ of objectives in increasing powers in the study of these sections. No one should attempt to study the histology of the nervous system without previously knowing something about the use of the microscope and having some practical knowledge of general histology and pathology; to such a person the study of sections does not depend upon _the judicious employment of gradually increasing powers in the microscope objectives_; if he use a No. 2 and a No. 7 of Verick, or some objective of about the same magnifying power, it is then simply a question of studying the specimens with those powers and learning to see and understand what he sees; there is no mystery about it. I will refer to one other paragraph on page 56, where it is stated: “The central gray matter of the spinal cord. This has no connection with the higher senses. It is capable in itself of the simplest kind of reflex acts by means of the spinal nerves. These can be produced at the will of the experimenter, in the beheaded frog, when an irritation of the skin by an acid, etc., is created; and Robin has satisfactorily performed the same experiment upon a beheaded criminal. We have reason to believe that the spinal cord can be slowly and in a purely automatic way taught to perform certain series of muscular movements (as in playing scales upon a musical instrument, for example,) without any intervention of the higher ganglia.” This is physiology. Is it true that the central gray matter of the spinal cord has no connection with the higher senses? The complicated movements which are performed by a person playing on a musical instrument, like the piano, for instance, are more than a simple reflex action of the spinal cord; and we do not believe that the spinal cord can be taught to perform such movements without the intervention of the higher ganglia. When one is learning to play the piano or other musical instrument, the higher centres are constantly in action, guiding and regulating the muscular contractions which go to make up the act of playing; after constant repetition under the guidance of the higher centres, the spinal cord and lower centres, as it were, learn and retain the combinations necessary to the performance of the act, all that is necessary is to start the particular combination, and the spinal cord will carry it on automatically. The spinal cord cannot be taught to perform such complicated acts without the intervention and guidance of the higher centres to begin with. Dr. Ranney has done a great deal of work in the preparation of this volume, and deserves much credit for his endeavors to collect this somewhat scattered material. The work has numerous illustrations and diagrams, most of them exceedingly good, but we observe among them some of the worthless and often fanciful illustrations from Luys’, which are reproduced here.