It must further be observed that the whole upper part of the shield in the female voicebox is less developed than in the male. The upper horns are short, so that the voicebox is more closely attached to the tongue-bone, and its position in the throat is altogether higher in woman than in man. To show more clearly still the difference in the proportions of the male and the female voicebox, I give below some average measurements (taken from Luschka's great work on the Larynx) which I have, for the convenience of English readers, reduced, as nearly as possible, from centimetres and millimetres to inches. MALE. FEMALE. Height of the voicebox in } 2-4/5in. 1-9/10in. front, with the lid raised } (7 cent.) (4.8 cent.) Greatest width between the } 1-3/5in. 1-2/5in. plates of the shield cartilage} (4 cent.) (3.5 cent.) Depth between the lower } border of the shield cartilage, } 1-1/5in. 1 in. and the opposite point } (3 cent.) (2.4 cent.) of the ring cartilage. } Length of the vocal chink ... 1 in. 3/5 in. (25 mm.) (15 mm.) According to this eminent anatomist, therefore, the differences between male and female larynges are as follows: In height, 9/10; in width, 1/5; in depth, 1/5; in the length of the vocal chink, 2/5 of an inch. As it is plain that if there were "no difference between the male and the female larynx save in size," all their proportions would be alike, I think I may safely assume that I have proved my point, which is a rather important one, as the reader will see when the registers in the male and female voice come up for discussion. We will now consider the question how the various classes of voice--_i.e._, Sopranos, Contraltos, Tenors, and Basses--are to be accounted for by corresponding differences in the voicebox. We know that tone is produced by the vibrations of the vocal ligaments. It is clear, therefore, that a voice will be high or low according to the number of vibrations which the ligaments are capable of producing, or in other words, according to their dimensions and their tension. This difference is easily seen by comparing the voicebox of a soprano with that of a bass, because there the proportions are so manifestly smaller in the one than in the other. There are similar distinctions between soprano and contralto on the one hand, and between tenor and bass on the other, but they are not so striking. Neither can they, for various reasons, be demonstrated with the laryngoscope; but they exist nevertheless.