CHAP. II, GENERAL REMARKS ON THE SENSES. 53 



mastication. Some of the Sparl, indeed, and the whole 

 of the Pkctognathes, or cheloni- 

 form fishes, live upon crabs and 

 shellfish ; and hence we find, 

 among the former (fig. 11.)* regu- 

 larly formed grinding teeth : hut, 

 in all cases, the tongue the great 

 organ of taste seems slightly de- 

 veloped, at least, in comparison to what we see among 

 quadrupeds ; while the sense of touch is, in all proba- 

 bility, still more imperfect. Nevertheless, as the de- 

 vouring of their appropriate food must be a pleasure 

 to every animal, we are at a loss to conceive how this 

 can arise, except through the medium of a correspond- 

 ing faculty of taste. 



(69.) The eyes of frogs are large and bright, and 

 they are defended by a moveable membrane, well 

 adapted to preserve them from those injuries to which, 

 from their peculiar mode of life, they would be par- 

 ticularly liable.* The ears, as Ray observes, are ex- 

 tremely small ; yet, as they answer one another at great 

 distances, by croaking, they are, probably, provided 

 with a sufficient portion of the hearing faculty. 



(70.) In taking a general survey of the development 

 of the senses in the vertebrated circle, which we have 

 now gone through, we plainly perceive that there is a 

 gradual progression, which commences with the tor- 

 toises, or Chelonides, among the reptiles, and reaches its 

 height among the Mammalia. From this point, again, 

 there is as gradual a descent towards the fishes, until 

 we see all the imperfect senses of the reptiles in the 

 class of Amphibia. This circular gradation in physical 

 qualities is in complete unison with the succession of 

 these groups in their organic structure; so that we find 

 the highest point of perfection to which the senses are 

 carried, precisely among those animals which, as being 

 most complicated in their structure, stand at the head 

 of the whole class. The progression of the senses, in 



* Ray's Wisdom of God, p. 165. 

 K 3 



