ORGANS OF VOICE AND RESPIRATION. 47 



puscles. In the Apes they appear of the same size as in Man. 

 There is a remarkable exception to the form of these corpuscles in 

 the Camels and Llamas, where they are somewhat elliptical. 



ORGANS OF VOICE AND RESPIRATION. 



THE larynx, trachea, and lungs, in the Mammalia, are fashioned 

 after the type of the same organs in Man. In the larynx the same 

 cartilages are met with as in Man, though the relations of their 

 separate parts are frequently changed. In the Cetacea the larynx 

 is very small, especially the thyroid and cricoid cartilages ; on the 

 contrary, the arytenoid cartilages and the epiglottis are very long, 

 and reach as far as into the nasal cavity. The thyroid cartilage 

 is very anomalous in form, and there are no chordae vocales, 

 since neither the Dolphins nor Whales have been heard to utter 

 any sound. In the Pachydermata also the larynx is small, espe- 

 cially its arytenoid cartilages. The thyroid cartilage is long and 

 deep, but narrow in the Ruminantia, and for the most part also in 

 the Edentata. The Rodentia have a conspicuous larynx, and in 

 the Carnivora especially, the cricoid cartilage is very large, often 

 three times greater than the thyroid. The Cheiroptera are dis- 

 tinguished by their very small epiglottis. The lateral ventricles of 

 the larynx, and with them the anterior chordae vocales, are fre- 

 quently wanting, as in the Ox, Sheep, Musk-deer, Armadillo, and 

 Pangolin. In several Mammalia, as in the Apes (but not the Ma- 

 kis), and many Carnivora (e. g. Ursus, Canis), the two cuneiform or 

 Wrisbergian cartilages (cartilagines cuneiformes), which lie in the 

 fold of membrane between the arytenoid cartilages and the epiglottis, 

 are considerably developed, while in man they are wanting, or very 

 minute. Peculiar sesamoid cartilages rest, in some Mammalia, as 

 the Ornithorynchus, the genera Mustela, Didelphis, &c., upon the 

 posterior border of the arytenoid cartilages. There occurs a smaller 

 azygos interarticular cartilage (c. interarticularis) in many Mam- 

 malia, as the Hedgehog (where it is very conspicuous), and also 

 in the Hog, Dog, &c., situated in the middle between the two 

 arytenoid cartilages upon the upper border of the cricoid. The 

 human larynx is distinguished from that of the Apes, in particular 

 by the greater shallowness of the thyroid cartilage, the greater de- 

 velopment of the arytenoids, the lesser size of the lateral ventricles, 

 the absence or slight development of the Wrisbergian cartilages, and 

 the greater degree of hardness and frequent ossification of the carti- 



