ERUPTION OF THE TEMPORARY TEETH. 187 



undertake to demonstrate, with the guide of the tables men- 

 tioned, together with my own experience and observation while 

 practicing in breeding estabHshments, that our practical men have 

 been quite right in many cases, and that the doubts to which 

 reference has been made are not without foundation." 



The pig, like the other animals, has two sets of teeth, — the 

 temporary or milk teeth and the permanent ones. 



•' There exists a remarkable difference in the time occupied 

 by the teeth in cutting their way through the gum and appear- 

 ing on its surface, while the mode of succession remains un- 

 changed. But it must be remembered that the dentition tables, 

 still referred to in modern books for the practical pig-breeder, 

 are based upon observations made in times when the common 

 pig was raised, or, perhaps, a breed more or less improved by 

 English stock, and fed in the old-fashioned style. Variations 

 into early maturity were then described as abnormal ; but as soon 

 as the pure breeding of the favorites of our day commenced, 

 Berkshire, Poland China, et al.^ and we applied to them scien- 

 tific feeding, we forced the animals into entirely new and arti- 

 ficial conditions, revealing the hitherto unknown physiological 

 laws of early maturity." 



The periods of age which can be determined by the denti- 

 tion are divided as follows : — 



1. Eruption of the temporary teeth. 



2. Eruption of the permanent teeth. 



3. AVearing of the permanent teeth, after two and a half 

 or three years, — an age attained but by few animals. 



These periods vary slightly, and when a latitude of time is 

 given it is understood that the shorter is for precocious pigs and 

 the longer for those races which approach the primitive pig. 



FIRST PERIOD ERUPTION OF THE TEMPORARY TEETH. 



At Birth. — The pig is born with eight teeth, — the corner 

 incisors of each jaw and the tusks. These teeth resemble each 

 other very much, and probably serve to aid the tongue in 

 sucking. 



