236 PROFESSOR TURNER'S ACCOUNT OF THE GREAT FINNER WHALE 



Three inches in the foetus, above the place of bifurcation of the trachea, that 

 tube gave off a supplementary bronchus, 1^ inch in diameter, to the right lung, 

 which seems to be, as Sandifort and Eschricht have pointed out, the usual 

 arrangement in the cetacea, the Greenland right whale being excepted.""" The 

 trachea had three, somewhat irregularly formed, cartilaginous hoops immediately 

 above the bifurcation ; but from the highest of these up to the arytenoid carti- 

 lages, a distance of 6^ inches, which corresponded to two somewhat subdivided 

 tracheal rings, and to the interval between the separated inferior borders and 

 plate-like processes of the cricoid, the cartilage was deficient inferiorly, and the 

 ventral wall of the wind-pipe was formed of fibrous membrane. The mucous 

 membrane of the trachea, more especially on the anterior wall, was marked by 

 numerous fine reticulated folds, the chief of which ran parallel to the long axis 

 of the tube. The diameter of the trachea was about 5 inches. 



The cartilaginous framework of the larynx consisted of a thyroid, a cricoid, 

 a pair of arytenoid cartilages, and an epiglottis. The form, arrangement, and 

 connections of these cartilages were examined in the foetus (Plate VIII., figs. 

 36, 37, 38). 



The thyroid cartilage consisted of a median and two lateral portions. It 

 was a comparatively thin plate, and possessed two surfaces, a superior and in- 

 ferior, which were flattened, and two margins, an anterior and a posterior. The 

 median part, tongue-like in form, was bifid at its hinder border, and projected 

 for some distance backward ; a deep notch marked its superior border ; from 

 this notch, to the end of the forks of the tongue-like part, the diameter was 4^ 

 inches. The lateral portion curved outwards, and was then prolonged back- 

 wards, as the elongated and somewhat rounded posterior cornu to be articulated 

 by a moveable joint with the outer surface of the cricoid. The anterior cornu 

 was continuous with the anterior border of the cartilage ; it was short and rudi- 

 mentary. The cartilage was connected to the body and great cornua of the 

 hyoid bone by a strong membrane, and a pair of thyro-hyoid muscles passed 

 between them. 



The cricoid cartilage was an incomplete ring ; suj)eriorly, it formed a thick 

 mass of cartilage 7 inches in its antero-posterior diameter. Its surfaces were 

 curved, and it turned round the sides of the wind-pipe towards its ventral 

 aspect, and ended in the greater part of its extent in a free rounded border. 

 From the hinder part of this inferior border, however, five plates, similar in 

 form to the cartilaginous hoops of the trachea, arose and turned round the 

 side of the larynx to the ventral surface ; but the plates from opposite sides 

 did not meet in the mesial line. An interval, varying in its transverse diameter 



* Die Nordischen Wallthiere, p. 148, Ray Society's translation of Memoir on Greenland Whale, 

 p. 103. 



