Chap. 6.] FISHES. 367 



CHAP. 6. WHETHER FISHES RESPIRE, AND WHETHER THEY 



SLEEP. 



BalaenaB have the mouth 37 in the forehead ; and hence it is 

 that, as they swim on the surface of the water, they discharge 

 Tast showers of water in the air. (7.) It is universally agreed, 

 however, that they respire, as do a very few other animals 38 

 in the sea, which have lungs among the internal viscera ; for 

 without lungs it is generally supposed that no animal can 

 breathe. Those, too, who are of this opinion are of opinion 

 also that no fishes that have gills are so constituted as to 

 inhale and exhale alternately, nor, in fact, many other kinds of 

 animals even, which are entirely destitute of gills. This, I find, 

 was the opinion of Aristotle, 39 who, by his learned researches 40 

 on the subject, has induced many others to be of the same 

 way of thinking. I shall not, however, conceal the fact, that 

 I for one do not by any means at once subscribe to this 

 opinion, for it is very possible, if such be the will of Nature, 

 that there may be other organs 41 fitted for the purposes of 

 respiration, and acting in the place of lungs ; just as in many 

 animals a different liquid altogether takes the place of blood. 42 

 And who, in fact, can find any ground for surprise that the 

 breath of life can penetrate the waters of the deep, when he 



37 " Ora." Cuvier remarks, that it is not the " mouth of the animal but 

 the nostrils, that are situate on the top of the head, and that through these 

 it sends forth vast columns of water." Aristotle, in his Hist. Anim. B. i. 

 c. 3, has a similar passage, from which Pliny copied this assertion of his. 



38 Cuvier remarks, that these are the animals of the cetaceous class, 

 which resemble the quadrupeds in the formation of the viscera, their 

 respiration, and the mammaB ; and which, in fact, only differ from them in 

 their general form, which more nearly resembles that of fishes. 



39 Hist. Anim. B. viii. c. 2. 



40 " Doctrinae indaginibus." This certainly seems a better reading than 

 " doctrina indignis," which has been adopted by Sillig, and which would 

 make complete nonsense of the passage. 



41 Dalechamps states that Caelius Rhodiginus, B. iv. c. 15, has entered 

 very fully into this subject. 



42 Cuvier remarks, on this passage, that the mollusca have, instead of 

 blood, a kind of azure or colourless liquid. He observes also, that insects 

 respire by means of tracheae, or elastic tubes, which penetrate into every 

 part of the body ; and that the gills of fish are as essentially an organ of 

 respiration as the lungs. All, he says, that Pliny adds as to the introduc- 

 tion of air into water, is equally conformable to truth ; and that it is by 

 means of the air mingled with the water, or of the atmosphere which they 

 inhale at tke surface, that fishes respire. 



