of power of correctly combining the movements necessary for the retention of the equilibrium. When irritated, no movements were produced, neither were any signs of pain elicited; but if any of its crura were touched acute suffering was produced.

The above experiments show also that the cerebellum does not lie in the motor tract, as after its removal the animal is still able to execute voluntary movements, and irritation of its substance produces no motor effect.

The following is a short recapitulation.

All sensory impressions, whether elaborated by the faculties of the mind situate in the cerebral hemispheres or by the sensory nerves, are permanently stored up in the optic thalami, and constitute the sensory memory. All voluntary motor impulses, whether discharged on account of information derived from the sensory memory, or when the equilibrium has to be maintained, in a large part through a special source, the cerebellum, leave a permanent modification of the cells and fibres of the corpora striata, constituting the motor memory. After the faculties have discharged their functions in establishing the sensory and motor memories, and the latter have reached the necessary intensity, they become directly combined, and act, in a large part, irrespective of the consciousness of the individual, when the appropriate stimuli are applied. The cerebral hemispheres are the seat of consciousness, and of all those processes which come under the head of voluntary; they are divided into a nuuber of faculties, each with a definite function, though closely associated, and with a corresponding influence on the mind, the influence of any individual faculty varying with its blood supply.

PART IL

THE CULTIVATION OF MEMORY

IT will be seen from the foregoing chapters that the memory can be considerably improved by a careful attention to the laws of remembrance, and other physiological processes in which the memory is concerned.

As the faculties differ in individuals, any mnemonical scheme which is based upon one or more faculties will not apply to all; and many persons will find more difficulty in remembering with the aid of the scheme than without it. The following rules are generally applicable, because they are based on functions which are the same in all, and can be even utilised for the purpose of teaching animals, and very considerably in the education of children.

RULES FOR THE CULTIVATION OF THE SENSORY

MEMORY.

RULE I.-Employ a perception of sufficient intensity to allow of the future conscious revival of the impression received.

The essence of this consists in concentration of the attention; the faculty, or faculties, must be brought to bear properly on the subject in hand, or the impression

will be only feebly received. Concentration is a quality possessed by all the faculties; the musician pays the utmost attention to a performance by one of the great artists, but might find great difficulty in listening to a sermon. The scientific man, devoted to the study of geology, finds no difficulty in observing rocks and stones for hours, with the most exclusive attention; but his thoughts would probably wander far from the game, if he were trying to watch a football match, which might be of the most intense interest to the athlete. The schoolboy, who may not trouble himself about his Latin, may be thinking very consistently of how he shall make a new boat or kite; and so on-examples might be multiplied ad infinitum.

It will be seen from this that a person experiences no difficulty in paying attention to a subject in which he is interested; it is fixing the attention on subjects for which there is no inclination that is difficult; and it is besides, a very wearisome and exhausting process, which ought to be avoided as much as possible by the choice of occupations suitable to individuals. When there is no opportunity for choice, and the subject in hand must be learnt, then the advice given under Rules IX. and XII. should be followed.

Want of concentration is often found as an accompaniment of functional disorders of the digestive and circulatory systems. The great disinclination for mental or physical exertion, often found in anæmia and dyspepsia, is probably due to the nervous force soon becoming expended, and there not being sufficient nutritive activity to restore the exhausted nervous system. The same may be said of the loss of concentration met with when excessive study is persevered in; in this case it is

probably due to an over-expenditure of nervous force, and plainly shows that the individual is being over-worked, especially if there be a natural aptitude for the subject. In these cases it would be absurd and most pernicious to adopt any artificial method of fixing the attention; the brain plainly requires rest—at least the particular faculties in use-whilst the others are probably underworked. Hence the great advantage of a complete change of occupation and scene, which usually rapidly restores the individual to his wonted health. It is a great mistake to imagine that complete rest is required; the practice of music generally affords complete rest to a wearied literary man; but outdoor and athletic occupations are the best, as they answer other requirements as well.

It is of the utmost importance to acquire a habit of mental concentration; work never can be done efficiently if the student do not devote the whole of his attention to the subject.

RULE II.-Establish a definite and decided primary

impression.

As it is important to pay attention to the subject in hand, so it is necessary to thoroughly understand, and have a clear idea of, what is to be learnt. It is especially necessary to do this, because so much depends upon the primary impression. Thus, supposing a book has to be mastered, a good plan is to carefully epitomize it, writing out the epitome in a note-book, taking care that each chapter is thoroughly understood before commencing to epitomize it. The note-book may then be used, and the subject put in a condensed form, the greater part of most books being employed to make the

remainder intelligible. This may then be learnt, and it will be found that the student will have a complete knowledge of the whole book.

A similar method must be adopted when learning a name, or a tune; each must be clearly and distinctly heard, and a person should possess a clear idea of the impression received.

It is very essential that this rule be carefully attended to; if a subject be, at first, only imperfectly learnt, it will be impossible to remember it properly, however good the memory may be. No trouble is spent in vain, in obtaining correct ideas of a subject to commence with, and many of our greatest men have said that their success was in a great measure due to an attention to this point.

RULE III.-Each impression should not at first include too many details.

Too little distinction is usually paid to the difference between the heads of a subject and the lesser details; a large number of students learn the whole alike, just as they are found in books; and this is a fault to be found in a great many books: the exceptions are often made more of than the examples illustrating the rule itself. This is probably due to the rule having become so familiar to the writer as to make him only see the exceptions in special prominence. The best way to avoid this unnecessary acquirement of details, is to compare several books on the subject. The main heads of a book should always be first learnt; and then, the root and trunk of the subject having been firmly established, as many branches may be added as the student is capable of remembering. This refers to