Memory has been classified in various ways, according to the time element, as immediate and permanent. Immediate memory is the one which holds for a short time, whereas permanent memory holds for a long time. People differ markedly in this respect. Some can if tested after the study period reproduce the material with a high degree of accuracy, but lose most of it in a comparatively short time. Others, if tested in the same way, reproduce less immediately, but hold what they have over a long period. Children as a whole differ from adults in having poorer immediate memories, but in holding what is fixed through years. Of course permanent memory is the more valuable of the two types for most of life, but on the other hand immediate memory has its own special value. Lawyers, physicians, politicians, ministers, lecturers, all need great power of immediate memory in their particular professions. They need to be able to hold a large amount of material for a short time, but then they may forget a great deal of it. Memory is also classified according to the arrangement of the material as desultory, rote, and logical memory. In desultory memory the facts just "stick" because of the great retentive power of the brain, there are few connections, the material is disconnected and disjointed. Rote memory depends on a special memory for words, aided by serial connections and often rhythm. Logical is primarily a memory for meanings and depends upon arrangement and system for its power. Little children as a class have good desultory memories and poor logical memories. Rote memory is probably at its best in the pre-adolescent and early adolescent years. Logical memory is characteristic of mature, adult minds. However, some people excel in one rather than another type, and each renders its own peculiar service. A genius in any line finds a good desultory memory of immense help, despite the fact that logical memory is the one he finds most valuable. Teachers, politicians, linguists, clerks, waiters, and others need a well-developed desultory memory. Rote memory is, of course, necessary if an individual is to make a success as an actor, a singer, or a musician.