COMPARATIVE ANATOMY OF THE LARYKX. 633 



In Solipedes* the vocal cords are narrow and situated deeply. 

 There are no false cords, and no ventricle properly speaking, 

 but a hole pierced in the lateral wall above the true cords con- 

 ducts into a large oblong sinus, hidden between the wall and 

 the thyroid, and covered, to a great extent, by the thyro-aryte- 

 noid muscles, which should be able to compress it. 



This opening is large in the Horse,t but the cavity is not 

 very deep. ThereJ is also in this animal a triangular membrane 

 situated in the angle of the thyroid. This easily vibrates as it 

 rests upon the moving cords beneath it. The commencement 

 of the " hinny " is due to repeated shocks of expired air upon 

 this membrane. 



In the Ass§ two sacs are situated above the attachment of 

 the cords. A tendinous membrane is also present. There is a 

 great deepening of the thyroid. 



Cuvier || considers the larynx of the Mule more allied to that 

 of the mare, and speaks of Herrissant's observations as inaccu- 

 rate, and as regards the triangular membrane of the horse's and 

 ass's larynx, exaggerated. 



The EhinocerosIF has well-marked vocal cords and deep 

 ventricles, before each of which is a nearly vertical opening, 

 and it is at the bottom of this excavation that the anterior liga- 

 ments are attached. 



In the Pig** the true cords are free and sharp. The superior 

 ligament is large and its margin rounded. The ventricle is 

 shallow, and from this opens an oblong sinus which rises up 

 between the mucous membrane and the thyroid, and is the size 



of the end of the little finger (It is to be observed 



that in many animals of this class, i.e., quick runners,tt the two 

 cartilages are arranged in such a manner as not to coaptate 

 completely, and so allow a space to remain free between them 



• Cuvier, p. 793. 



t Ibid., p. 793. 



X Herrissant, Recherches sur les Organs de la Voix, p. 282. 



§ Op. cit., p. 285. 



II Cuvier, p. 793. 



t Op. cit., p. 791. 

 ** Op. cit., p. 791. 

 ft Miine-Edwards, p. 455. 



