AND PHYSIOLOGY. 



259 



vanced do not by any means entirely overthrow the old theo- 

 ry. They show us that the theory of combustion does not 

 cover the whole ground, but that other causes, as well as 

 oxydation produce animal heat. And we propose the idea 

 that animal heat, like digestion, is a chemico-vital process, 

 that is, a process under the immediate influence of chemical 

 changes, but entirely under the control of the vital principle, 

 since animal heat can not be maintained after death. 



ORGANS OF THE VOICE. 



DEFINITIONS AND DESCRIPTIONS. 



459. The Larynx; its 

 Cartilages. — The Larynx in 

 all animals is the essential or- 

 gan for the production of the 

 voice. It has also very much 

 the same structure in every 

 animal which has the power of 

 expressing its feelings by the 

 voice. A cartilaginous tube, 

 imperfectly conical, the base 

 directed upwards, made up 

 of distinct portions or seg- 

 ments slightly movable upon 

 one another, and with a cer- 

 tain portion of the channel 

 lengthened into a narrow and 

 elongated opening, constitutes 

 a larynx. In man this organ 

 is made up of seven distinct 

 portions or cartilages, two 

 Arytenoid (pitcher-shaped), 



Eig. 255. 



A Lateral View of the Larynx. 1, Os 

 Ilyoides. 2, Thyreo-Hyoid Ligaments. 



3, Cornn Majus of the Thyroid Cartilage. 



4, Its Angle and Side. 5, Cornu Minus, 

 6, Lateral Portion of the Cricoid Carti« 

 lage. 7, llings of the Trachea. 



