622 



PHYSIOLOGY 



is a considerable development in the size oi the larynx in both sexes. This 

 is especially marked in the male, and accounts for the sudden drop in pitch 

 (' breaking ') of the voice. In the female the increased size of the larynx 

 is chiefly perceptible in the increase in fulness and richness of the voice 

 which occurs at this age. Even when we take all the voices together, 



FKJ. 312. Three laryngoscopic views of the superior aperture of the larynx and 

 surrounding parts in different states of the glottis during life. (From CZERMAK.) 



A, the glottis during the emission of a high note in singing. B, in easy or 

 quiet inhalation of air. C, in the state of widest possible dilatation, as in inhaling 

 a very deep breath. The diagrams A', B', C' have been added to Czermak's 

 figures to show in horizontal sections of the glottis the position of the vocal liga- 

 ments and arytenoid cartilages in the three several states represented in the other 

 figures. In all the figures so far asmarked, the letters indicate the parts as follows, 

 viz. : .1, the base of the tongue ; e, the upper free part of the epiglottis ; e' '. the 

 tubercle or cushion of the epiglottis ; p h, part of the anterior wall of the pharynx 

 behind the larynx ; in the margin of the aryteno-epiglottidean fold w, the swelling of 

 tin- membrane caused by the cuneiform cartilage ; *, that of the corniculum ; a, 

 the tip <f the arytenoid cartilages ; c v, the true vocal chords or lips of the rima 

 irlottidis : c v s, the superior or false vocal cords ; between them the ventricle of 

 the hiiviix : in 0, t r is placed on the anterior wall of the receding trachea, and l> 

 indicates the commencement of the two bronchi beyond the bifurcation, which 

 may be brought into view in this state of extreme' dilatation. 



, tenor, alto, and soprano, the total range for ordinary individuals does 

 not exceed three octaves. In singing the voice may be produced in various 

 ways, i.e. in different registers. Thus we distinguish the chest register, the 

 middle register, and the head register. The deeper notes of any individual 

 voice are always produced in the chest register. Observation of the vocal 

 cord shows that when producing such notes the glottis forms an elongated 

 slit, all the muscles which close the glottis and increase the tension of the cords 

 being in action. The vocal cords are relatively thick and broad and can 



