This deficiency of Vocal Science is frankly recognized by one of the latest authoritative writers on the subject, Dr. Wesley Mills. On page 173 of his work just quoted, he advises students to _hear the great singers_, to note carefully the _quality of tone_ which characterizes each register, and to _imitate these qualities_ with their own voices. This advice may almost be described as revolutionary. Vocal theorists have always assumed that the correct action cannot be acquired by imitation. In this advice to rely on the imitative faculty for acquiring control of the laryngeal action, Dr. Mills abandons the basic principle of modern methods. Without exception, all instruction in singing is to-day based on the idea of mechanical tone-production. An entirely new theory of Voice Culture is involved in this advice of Dr. Mills. Turning to practical methods of instruction, it is found that the subject of registers is very seldom treated in the manner suggested by the theoretical works on the voice. This would be, to make the "placing" of the voice in the different registers the exclusive subject of instruction for a certain number of lessons;--to train each register of the voice separately;--when the correct vocal cord action had been established in each register, to unite the different registers, and to correct any "breaks" which might have developed. Comparatively few teachers attempt to follow this course. The great majority treat the registers in a much less systematic fashion. A single half-hour lesson usually includes explanations and exercises on several topics of mechanical tone-production, as well as hints on agility, style, execution, etc. As merely one of this variety of subjects, the registers usually receive rather desultory attention. Some teachers profess to ignore the subject of registers entirely. They maintain that, when properly trained from the beginning, the compass of the voice is one homogeneous whole; "breaks" and changes of quality are in their opinion merely the results of bad instruction. But the general belief of vocal authorities is overwhelmingly against these teachers. The condition which they describe is without doubt the ideal of vocal management; but the vast majority of teachers believe that this condition cannot be attained without some attention being paid to the individual registers. Most teachers recognize either two registers,--chest and head; or three,--chest, middle, and head. Comparatively few extremists recognize more than three. Several sets of names for the registers have been proposed by vocal theorists,--thick and thin, long reed and short reed, high and low, etc. But these names have not been adopted by teachers to any extent.