“It may be stated as a physiological axiom, that the bones of those individuals who possess the strongest muscles are much better developed than those of persons with weak muscles. The full development of the bones is dependent upon the musculature, and the latter, of course, upon exercise of function and the amount of resistance to be overcome.

“Now, the exercise which the muscles attached to the mandible are called upon to perform is chiefly that of the mastication of food. But mastication is a very varied and complex act; it therefore becomes necessary to consider it in more detail than has hitherto been done.”