Outside of England, at least, Maclaren is best known through his latest volume, “A System of Physical Education, Theoretical and Practical,” published in 1869.[169] The book is arranged in three parts: (1) Growth and Development (pp. 3-101), (2) Practical System of Gymnastic Exercises (105-472), and (3) Appendices A-K (475-518). While the second part, which makes up nearly three-quarters of the volume, is not without interest as a manual of gymnastics embodying the author’s ideas and the results of his long and varied experience,[170] it is the first hundred pages and certain of the appendices which have raised it to the rank of a classic in its field. After pointing out that “exercise alone of all the agents of growth and development can be regarded in an _educational_ light—alone is capable of being permanently systematized and administered as a means of progressive bodily culture,” he proceeds to discuss its nature and effects in terms of the physiological science of his day, much of it now outgrown. Health, rather than strength, should be the aim, he says. “Scholarships Junior and Senior, Examinations, open Fellowships, speculations, promotions, excitements, stimulations, long hours of work, late hours of rest, jaded frames, weary brains, jarring nerves—all intensified and intensifying—seek in modern times for the antidote to be found alone in physical action.” School-games, sports and pastimes he finds, “from their very nature, are inadequate to produce the uniform and harmonious development of the entire frame, because the employment which they give is essentially partial.... Recreative exercise in sufficient amount is usually in itself sufficient to maintain health and strength after growth and development are completed, but it does not meet the many wants of the rapidly-changing and plastic frames of youths spending a large portion of their time in the constrained positions of study.”