122 THE VITAL FUNCTIONS. 



are of great size and strength in the larger beasts 

 of prey, as the Lion and the Tiger ; they are met 

 with also in the Opossum, and in many species of 

 Bats, more especially those belonging to the genus 

 Pteropus: all these horny productions have been 

 regarded as analogous to the lingual teeth of fishes, 

 already noticed. 



The mouth of the Oniithorhynchus has a form of 

 construction intermediate between that of quadru- 

 peds and birds ; being furnished, like the former, 

 with grinding teeth at the posterior part of both 

 the upper and lower jaws, but they are of a horny 

 substance ; and the mouth is terminated in front by 

 a horny bill, greatly resembling that of the duck, 

 or the spoonbill. 



The Whale is furnished with a singular appa- 

 ratus designed for filtration on a large scale. The 

 palate has the form of a concave dome, and from 

 its sides there descends perpendicularly into the 

 mouth, a multitude of thin plates, set parallel to 

 each other, with one of their edges directed towards 

 the circumference, and the other towards the middle 

 of the palate. These plates are known by the name 

 of whalebone ; and their general form and appear- 

 ance, as they hang from the roof of the palate, are 

 shown in Fig. 272, which represents only six of 

 these plates.* They are connected with the bone 

 by means of a white ligamentous substance, to 

 wiiich they are immediately attached, and from 



* In the Piked Whale the plates of whalebone are placed very 

 near together, not being- a quarter of an inch asunder; and there 

 are above three hundred plates in the outer rows on each side of 

 the mouth. 



