3349. But the tongue here appears for the first time in the animal kingdom as a perfect organ provided with muscles, and a lingual bone, as in Man; Fishes are, as regards the development of this sense the Glossozoa, Lingual or Tongue-animals.
3350. As Fishes are the repetition of the intestine and vitellus, so they may be termed abdominal or rather Pelvic animals. They are an abdomen, unto which are appended branchiæ, fins and head.
They are the repetition of the Infusoria, Mussels, and Worms; in them we meet with mucus, branchial opercula, articulated filaments, and labial cirrhi or palpal organs.
Class 11. Myozoa, Rhinozoa.
3351. Those Sarcozoa which for the first time obtain true muscles and a perforated nasal organ are the Reptilia.
3352. True muscles are red, have a definitely circumscribed outline, and are divisible into head, fleshy portion or belly, and tail or tendon. As such they are found for the first time in Reptiles.
Thorax.
3353. With the osseous system in Fishes the sexual abdomen was chiefly developed; with the muscular system therefore, as in the present class, the abdomen proper or intestinal abdomen becomes perfectly developed, and the thorax more spacious in calibre.
3354. The thorax is still blended with the abdomen. In Fishes the disposition was already stirring to create for themselves an air-organ; only this was imperfectly attained, since the swim-bladder communicated with the gullet, but not with the branchial arches or larynx, nor with the nasal organ, as in the present class.
3355. Now, if the swim-bladder be symmetrically developed, if it communicates with the branchial larynx and opens through the nose, the aerial respiration is completely attained, and shares its dominion over the body along with the digestive function.