486 PHILOSOPHICAL TRANSACTIONS. [aNNO 1747-8. 



the manner of whales, which is performed as that of other animals ; and ob- 

 serves, that they bring forth their young alive : these follow the female, and 

 suck milk from the teats, which are placed in them near the organs of gene- 

 ration ; and in violent storms the dam takes her offspring into her mouth, and 

 protects them from danger. This last is common to several of the skate-kind. 



The letter-writer alleges, that fish never sleep ; but our author assures us, that 

 all such as have lungs do in the night-time, thrusting up their nostrils into the 

 open air. For others he cannot be positive, as their history is little known. 



The letter-writer premises 2 questions ; first, whether fishes have any ears ? 

 or if the gills serve the same purpose ? and answers positively in the negative to 

 both : and therefore concludes they cannot hear. But Mr. K. asserts, that 

 snakes, frogs, cameleons, and others of the lizard-kind, actually hear, without 

 any of the usual external apparatus of hearing. For though they want the auri- 

 cles and ears, yet have they auditory passages, by which sound is conveyed, and 

 even internal organs, to which the meatus auditorius reaches. But Mr. K. 

 further asserts, that all the whale kind, and in general such fishes as have lungs, 

 have likewise a meatus auditorius, and the internal organs of hearing ; and ap- 

 peals to a public dissection of a porpoise, and another fish of the whale kind, 

 made by himself ; in which the os petrosum, with the other parts of these or- 

 gans, had been separately shown ; and calls in the concurrent testimony of Dr. 

 Tyson, in his anatomy of a porpoise. [See also the writings of Camper, Monro, 

 Cuvier, &c.] 



Thus having satisfied us about such fish as have lungs, he goes on to consider 

 the cartilaginous species, such as the skate, ray, and lamprey kind, which have 

 organs of generation, and copulate like brutes ; yet exclude the fetus while yet in 

 the egg-state : and this from analogy, that these, and in general all other fish, 

 as they have organs which serve them for lungs, so they may have what answers 

 in others to the apparatus of hearing. [The organ of hearing in these fishes has 

 been described by J. Hunter, and other anatomists.] 



In proof of this he asserts, that all kinds of fish except these which have lungs, 

 are always found to have stones in their heads naturally formed, and invariably 

 placed in the same situation, being joined to the contiguous parts with ligaments ' 

 and nerves, which take their rise from the substance of the brain ; and having 

 examined the head of a pike minutely with a microscope, he discovered the audi- 

 tory pores in the stones, and persuades himself, that 3 pair of stones are to be 

 referred to this use ; therefore concludes, as there is some analogy in the organs, 

 that all fishes in some measure hear. 



The letter-writer further objects, that water is not -the medium of sounds ; and 

 though air is actually contained in all water, yet it cannot be put into undulations, 

 any more than the circumambient water ; but that would require a much greater 

 vibration than the external air can give. Thus, says he, if a person immerge 



