PATHOLOGICAL FORMATION OF FERMENTS. 109 



growth of the lower jaw. In the child of five years its body 

 is short, just long enough to accommodate the ten deciduous 

 teeth. A lengthening of the body of the bone occurs, to make 

 room for three large permanent molars on each side. In this 

 lengthening the ramus of the jaw is carried back about one 

 and a half inches, which, in effect, protrudes the lower jaw 

 forward. Now this is not an interstitial growth of the 

 bone ; but the ramus is resorbed away from its anterior aspect 

 and built up posteriorly. The osteoclast cells, soluble fer- 

 ment-forming cells, are found there, and their effects upon 

 the bone may be seen. Their work, in this instance, however, 

 is done quite evenly and smoothly. This is the type of all 

 changes of form in the osseous system. It will be seen at 

 once that the amount of this work done during the growth, 

 formative stage, of the osseous system is simply immense. 

 The head of each bone must be trimmed down to the size of 

 the shaft as the bone lengthens, etc. 



By what power is this action controlled ? Here we come 

 directly upon the unknown. If we say it is through the con- 

 trol of the nervous system, we will be brought face to face 

 with the symmetrical formation of bones in the foetus, in 

 which the formation of a nervous system has failed, in which 

 the spinal canal, or groove, has never closed, is open from end 

 to end, and no trace of nerves is to be found. Yet, such a 

 foetus has, with the exception of the spinal column and skull- 

 bones, developed to term, a perfectly symmetrical skeleton. 

 After seeing this, the idea that these processes are under the 

 control of the nervous system seems untenable. And I am 

 free to say that I have no hypothesis to advance, except to 

 say that they are under the control of the life force, which, 

 I confess, is no explanation. 



