150 



SCIENCE. 



[N. S. Vol. XIV. No. 343. 



made during the summer, and again during the 

 winter, to hatch them in aquaria, but without 



success. 



H. W. Britcher, 



Secretary. 



DISCUSSION AND COEBESPONDENCE. 

 THE LARYNX AS AN INSTRUMENT OF MUSIC. 



It is with considerable hesitation that I ven- 

 ture to enter into a discussion that has arisen 

 in this Journal under the above title. It is so 

 likely to become a discussion of terms that may 

 be defined by different writers in different ways 

 that it is, perhaps, a question whether a pro- 

 longed discussion of the subject is desirable. ' 

 In spite of this fact, however, I take the liberty 

 of expressing an opinion to which I have been 

 brought by the past several years of observations 

 upon the larynx. Of course, we may call 

 that part of the larynx which vibrates a ' cush- 

 ion,' a 'reed,' a 'membranous reed,' a ' cord,' 

 a ' membranous cord ' or other names, and still 

 find much justification in each case. It seems 

 to me that if we wish to discuss the question as 

 to the class of instruments to which this be- 

 longs, we must judge it by two series of facts : 

 first, what elements control the pitch of the 

 fundamental tone produced; second, what is 

 the quality of the tone produced. If we ex- 

 amine the larynx with these points in view, we 

 find, in the first place, that the pitch of the 

 tone produced is controlled by three mechan- 

 isms : first, one for increasing tension ; second, 

 one for decreasing the length ; third, one for 

 lightening the weight of the vibrating part. 

 These three factors are those used for controlling 

 the pitch of a string. If we examine the quality 

 of the tone produced we find that the funda- 

 mental and over-tones form a series whose rates 

 of vibration are to each other in the oi'der of 

 the natural numbers, 1, 2, 3, 4 ; etc., this quality 

 of tone is the quality produced by a string and, 

 not the quality produced by a reed or mem- 

 brane, in both of which the quality is much 

 more complex and contains many intermediate 

 over-tones. It seems to me, in view of these 

 considerations, that we refer to this vibrating 

 part as a ' cord ' quite i:)roperly. It will be ad- 

 mitted, undoubtedly, by all that the tilting of 

 the cricoid cartilage on the thyroid cartilage in- 



creases the tension on the vocal cords, and in 

 so doing raises and tends to control their pitch. 

 The arytenoid cartilages when brought together 

 bring out the edges of the vocal cord from the 

 side of the tube, and by their rotation may de- 

 crease the free length of the vocal cords, as is 

 clearly shown by photographs that have been 

 taken of the larynx when producing tones of 

 different pitches. In Fig. 1 we have a section 



x 



Fig. 1. 



through the vocal cord and its immediate sur- 

 roundings. It is shown in the relaxed position 

 against the wall of the tube. The dotted line 

 between a..-g.--f shows, approximately, the 

 position and form of the cord in action. In 

 Fig. 2 is shown, diagrammatically, a cross-sec- 



FiG. 2. 



tion of the vocal cord, the point extension at h 

 being rather exaggerated. m is the vocal 

 muscle extending from the inside front of the 

 thyroid to the outer side of the arytenoid, and 

 passing through the back of the vocal cord. 

 This muscle serves to rotate the arytenoid, and 



