This little book, first written whilst I was a student, still, as formerly, pretends to no originality. Its one aim is and always has been to present, in as clear and simple a manner as possible, an outline of the Central Nervous System to the student, who, for the first time, is brought face to face with this most intricate subject, and to furnish him, to the best of my ability, with those facts which he will find most useful in his future work, and which, let us trust, he will not have soon to unlearn. Although, owing to a sad bereavement, the book was out of print for nearly ten years, it has now reached a fifth edition. 'this, at my age, will, in all probability, be the last as far as I am concerned. In it my one endeav our has been to keep the book as small as before. Any increase in length, apart from the inevitable addition of new matter, being chieﬂy due to the rewriting and extending of previous descriptions, with the object of rendering obscure passages easier to understand. New tables and recapitulations have also been given to serve for quick and easy reference.