Chap. 6.] 
I'ISHES. 
367 
CHAP. 6. WHETHER FISHES EESPIEE, AND WHETHER THEY 
SLEEP. 
Ealaense have tlie mouth ^"^ in the forehead ; and hence it is 
that, as they swim on the surface of the water, they discharge 
vast showers of water in the air. (7.) It is universally agreed, 
however, that they respire, as do a very few other animals^* 
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,^^ who, by his learned researches'^ 
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 JSTature, 
that there may be other organs'^ fitted for the purposes of 
respiration, and acting in the place of lungs ; just as in many 
animals a difierent liquid altogether takes the place of blood.'^ 
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. 
28 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 mammae ; 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. 
*o " Doctringe 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. 
Dalechamps states that Caelius Ehodiginus, B. iv. c. 15, has entered 
very fully into this subject. 
^ 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 
iakale at the surface, that fishes respire. 
