138 "PHYSIOLOGY. 



tion, is the second ; and the conveyance of that so collected and adapted 

 into the stomach, is the third. 



The mouth, which is the principal actor in these operations, is, in 

 many, formed alone for these operations ; and these formations are 

 according to the nature of the food, and circumstances attending that 

 food, viz. its natural situation ; as honey, which requires an apparatus 

 to get to it, which is a mode of many of the winged insects ; [in other 

 instances requiring a particular form of] the lips, as in some fish, e. g., the 

 sturgeon ; [or of] the tongue, as in the ant-bear, &c. 



The parts of an animal immediately preparatory to deglutition and 

 digestion are divided, in those that live on solids, into two kinds, viz. 

 bills or beaks, and teeth : to which, probably, may be added a third, 

 viz. those [parts] of insects which are exterior to the mouth. A mixed 

 land may, also, probably be added, viz. those that may be classed either 

 with the teeth or with the bill, such as the dividers of some reptiles, as 

 the snail, leech, &c. The bills are exterior, and are placed on, or 

 surrounding, the mouth of the animal : they are of the same shape with 

 the mouth, making a case for it ; and as the mouth is made up of two 

 parts opposing one another, commonly called upper and lower jaw, the 

 bill is also composed of two parts, or a pair. 



That class of parts of an animal preparatory to deglutition and 

 digestion, called teeth, is so extensive, and of such various forms and 

 uses, that it is uncertain in some cases what parts ought to be classed 

 among the teeth and what not ; and in those where they are evidently 

 for this purpose, it becomes difficult to class them either according to 

 their various uses or their forms. 



In some animals there are teeth for deglutition and others for diges- 

 tion ; for example, there are the nippers [mandibulce et maxillce] of a 

 crab or lobster, while those for digestion are in the stomach : and 

 where teeth are not necessary for [preparing the food for] digestion, 

 they are wholly for deglutition, as the grinders [carnassial or flesh- 

 cutting teeth] in a lion, cat, &c. 



The teeth are always placed between what may be called the brim or 

 margin of the mouth, and the first intestine ; viz. [in the] mouth, 

 oesophagus or stomach. Those subservient to deglutition are always 

 placed in the mouth, viz. between the margin of the mouth and the 

 oesophagus, having at the mouth a border of soft parts surrounding 

 them, called lips, which is much more in some animals than in others, 

 and which is the beginning of the mouth. 



The mouth is the most frequent situation of the teeth, at least in 

 those animals we are most acquainted with, viz. quadrupeds, amphibia 

 and fish. In some reptiles they are placed in the oesophagus, as in the 



