HUMAN DENTITION. 



471 



membrane of the alveolus. It is the cement which renders a 

 Uving tooth ' capable of uniting with any part of a living body' 

 as Hunter proved by his ingenious experiments. 



When the tooth performs its function throughout a long 

 life, free from any destructive influence but that of ordinary mas- 

 tication, a compensating provision would seem to have been in- 

 tended against the decay of the alveoli in old age by the final 

 substitution of a more highly organized substance, the osteo- 

 dentine, for the ordinary dentine which has been worn away. Nor 

 can we help admiring the analogy which this acquisition of a 

 more vascular organization, with the weakening of the alveolar 

 implantation, presents to the condition of the teeth in many of 

 the lower vertebrate animals. 



177. Adaptation of the teeth to the food and nature of Man. — 

 Whether Man was originally designed by nature to be herbivorous or 

 carnivorous is a question which some authors have supposed might 

 be absolutely determined from his dentition. If we had to judge only 

 by fossil remains we should be warranted in concluding from the 

 human teeth that the species was not intended, under all circum- 

 stances and in all places, to subsist upon either animal or vegetable 

 food exclusively. It would be obvious at the first glance that they 

 were intermediate in character between the typical carnivorous 

 and the typical herbivorous dentitions : the presence of canines 

 and the absence of the complex structure arising from the inter- 

 blending of vertical plates of the diflferent dental tissues in the 

 molars, would prove that the food could not have been the 

 coarse uncooked vegetable substances for which complex molars 

 are adapted ; and on the other hand the feeble development of the 

 canines and the absence of molars of the sectorial shape and 

 opposed like scissor-blades, would equally show that the species 

 had been unfitted for obtaining habitual sustenance from the raw 

 quivering fibre of recently killed animals. 



The Apes and Monkeys which Man most nearly resembles 

 in his dentition, derive their staple food from fruits, grain, the 

 kernels of nuts, and other forms in which the most sapid and 

 nutritious tissues of the vegetable kingdom are elaborated; and 

 the close resemblance between the Quadrumanous and Human 



