ERUPTION OF THE PERMANENT TEETH. 193 



animal par excellence for experiments in breeding, and the pig 

 is the best example of what men have accomplished in the 

 production of animals. 



" Drawing, now, the conclusions from the above examina- 

 tions, I shall summarize them in the following theses : — 



" 1. The order of succession of the teeth in our precocious 

 pigs remains the same as in the primitive hog. 



" 2. The times when the teeth appear are variable, according 

 to the race, feeding, and health. The same breeds, raised under 

 the same conditions, will show the same appearance. 



" 3. The form of the skull depends upon nutrition, health, 

 and more or less employment of certain muscles of the head and 

 neck." 



13 



