OF THE TEETH. 13? 



quired ; of which things our knowledge always becomes more perfect 

 by habit. 



The food of almost all young animals is principally of an animal 

 nature. In the sucking kind, whether of carnivorous or granivorous 

 parents, the young have the milk, which is a compound of animal sub- 

 stance and sugar. In birds, animal substances are principally the food 

 for the young granivorous, which live, at first, principally on insects, 

 worms, &c. 



Are there any granivorous animals that feed only at night, as there 

 are many carnivorous ? I should suspect not : because there are no 

 herbs found at night but are to be found in the day ; but this is not the 

 case with the animals [which serve for food]. However, it is possible 

 that there may be some animals which live only on the flowers that are 

 open at night. 



Of the Teeth. 



As the stomach is the digesting organ of the food of animals, — is in 

 common a containing part in the form of a bag or bags, — and as it is 

 generally placed on the inside of the animal, there must be an external 

 communication to that cavity : and as the food is either passive, as 

 vegetables, or active in contradiction to that process, as most animal 

 food, there must be a mode of collecting, catching, adapting, and con- 

 veying that food to, and through that communication to the stomach. 



Various are the means of doing all these operations ; and this variety 

 of modes arises, from the nature of the food which the animal lives 

 upon, [from] different modes of digestion (as the difference between a 

 ruminant and a horse), also [from] a great variety of circumstances 

 attending that food, the nature of which when caught may be often 

 similar. The first of which [circumstances] I shall reckon fluidity, as 

 honey, the juices of plants, such as what many insects live upon, <fec. 

 Secondly, [the food] being alive, therefore [involving] a mode of catching 

 and killing, which requires a greater extension of parts [concerned in 

 those actions], and then to separate parts from the whole. Thirdly, 

 collecting parts of growing vegetables. All of which [circumstances 

 require] parts formed and adapted for such purposes. Most of these 

 operations are performed by the mouth, or beginning of this communi- 

 cation in some animals ; and in many others by the mouth with its 

 other apparatus, as teeth ; but it has often still more exterior assistance, 

 as hands, claws, feet, &c. 



These operations may be divided into three, although all the three 

 are not necessary in every animal. The catching and collecting is the 

 first ; the fitting some food for digestion, and adapting most for degluti- 



