We do not know that horticulturists need any theory of gymnastics. A spade or a hoe is warranted to cure the worst case of dyspepsia. If people have no garden, there is the axe and the woodpile, and the wives and daughters of these unhealthy people will call them blessed. But what if there are no gardens, - no wood-piles, - ! no fields and forests where the poor fellow can go round into and collect wild flowers, - no cricket or base ball club? Why, then he may get this little book and mark its counsels well.