The previous discussions of neuro-muscular measurements have not depended upon introspective accounts. We have in each instance made the measurements as objective as possible, and have given the essential data and the best available material as comparison standards for averages. It seems unwise to attempt a summary table or diagram. Many of the measurements do not lend themselves readily in this case to a numerical statement of differences on account of the small amount of normal material which was actually secured from Squad A, and it is this group in which we are most deeply interested, since it was with them that the prolonged low diet was tried. While we may compare the results of Squad A on low diet with the normal values for Squad B and for other groups of men, yet it hardly seems permissible to subtract for differences and to claim that these state in terms of magnitude the effects of the reduced diet. In a few cases in which changes associated with the low diet have been definite and progressive as, for example, in the eye movements, it was found possible to compare the performance of the first of the experiments with that shown on the later dates and to state such differences in terms of per cent change. In general, we have had to be satisfied, under the circumstances, with statements of the direction of the effect, when such has existed, and secondarily with general statements as to the probable amount of the change.

The most significant results found for the neuro-muscular tests are given in simplest form for comparison. Opposite each measurement, named and numbered in order, there is a brief statement of the low diet effect, or of the apparent Lack of such an effect.

(1) Accuracy in tracing. Less accurate work and less rapid improvement.

(2) Pitch discrimination. Slightly poorer near the threshold.

(3) Number cancellation. Slower improvement.

(4) Addition. Slower improvement in accuracy.

(5) Memory span. No certain change.

(6) Strength of grip. Definitely lowered.

(7) Pulse with exertion. Lowered level of pulse-rate, nothing pathological.1

(8) Patellar reflex. Slightly depressed.

(9) Eye reactions. Not significantly changed.

(10) Word reactions. Not significantly changed.

(11) Number reactions. Not changed.

(12) Visual threshold. Efficiency not decreased.

(13) Electrical threshold. Less sensitive and less improvement.

(14) Eye movements. Slower speed.

(15) Finger movements. Slower speed, no indication of quicker fatigue.

(16) Maze performance. Not significantly changed.

(17) Clerical tasks. Slower improvement.

From this review of the results with the neuro-muscular measure ments it appears that there was some disturbance in motor coordination and in muscular performances generally. The reactions, thresholds, and discriminations show less definite change. The same is true for the more complex processes involved in memory, maze performance, and clerical tasks. In some of these processes not distinctly muscular there appeared to be slower improvement under the lowdiet conditions than would, according to our other standards, be expected from these men. These changes in performance and in practice, i. e., learning with successive performances, are most prominent at those periods when the subjects are actually losing weight. The changes, even at these times, are not what could be considered as at all pathological. Just as the weights of the subjects, when they had reached their low level, were still within what are commonly considered by actuarial authorities to be normal limits, so the changes found in the neuro-muscular processes usually seem no larger than the normal range of results for supposedly normal men would permit. It is difficult to estimate how much of a decrement may take place, for example, in the muscle coordinations of a subject, and still not seriously interfere with his usual activities. Theoretically, for competitive, high-grade work, no decrement should be permitted, and therefore no conditions allowed which will operate in the direction of such a decrement. Practically, and under urgent circumstances, an individual may adjust himself to a rather wide range of neuro-muscular changes accompanied by varying conditions or degrees of physiological and psychological comfort and well being and at the same time do his usual work in a way which to others, at least, is not sensibly inferior.

1See section on pulse-rate, p. 415, for results.