746 



/: 



r 



diminishing regularly, while the width also decreases but not so 

 regularly. The latter, namely, shows a sudden decrease between 

 ^ and 00. In this series the height ot the moutli opening was 16 



niM., 12 mM., 8 mM., 6 mM.,4 inM. respect- 

 ively, the width 36 mM., 31 mM., 16 mM., 

 14 mM., 7 niM. respectively (see tig. I). 



Closely connected with this are curves of 

 the li[)movements made with the apparatus 

 of VON Wii.czKWsKi '). This apparatus has 

 been so construed as to have the curves 

 indicate the natural size of the vertical lip- 

 opening. Fig. 2 illustiates this. Fig. 3 shows 

 ii cnr\e obtained with the same apparatus 

 by pronouncing alternatively dol and dol. 

 The difference is clear: the dimensions are 

 about tlie same as those mentioned above. 

 I'ouseciuenlly, if we exclusively consider 

 the siiape of the mouth opening, we can 

 imasiue that o is an oo that became more 

 or less like an a while o is an oo that has 

 acquired some of the qualities of the oe. 



2. By means of Zwaardemakkr's apparatus') 

 for registering speech movements, the pouting 

 of the upper lip, the movements of the lower 

 jaw relative to the upper jaw, and the con- 

 traction of the muscles that form the bottom 

 of tiie mouth, were recorded. Fig. 4 shows 

 that also as regards jaw opening a, o, oo, o, 

 and oe form a descending series, while the 

 pouting of the lips increases, (with this trial 

 person there is less pouting of the lips for 

 9 and oe than for oo in connection with 

 the downward movement of the upper lip, 

 during which the latter is sowewhat flattened). 

 The curve of the mouth bottom is not 

 dealt with here because of its complexity. 

 What interests us most in this curve is that 

 Fig. 1. it shows considerable and characteristic dif- 



') Vox. Heft 3/6, 1922. 



•) Onderz. Physiol. Lab. te Utrecht. Ve reeks i 1899—1901 p. 76. Leerb. II 

 p. 98. 



