The farmer himself knows quite well how important the psychical behaviour of the animals is for his success. He knows how the milk of the cows is influenced by emotional excitement, and how the handling of horses demands an understanding of their mental dispositions and temperaments. Sometimes he even works already with primitive psychological methods. He makes use of the mental instinct which draws insects to the light when he attracts the dangerous moths with light at night in order to destroy them. Ultimately all the traps and nets with which the enemies of the crop are caught are schemes for which psychotechnical calculations are decisive. The means for breaking the horses, down to the whip and the spur and the blinders, are after all the tools of applied psychology. The manufacturer is already beginning to supply the farmer with some practical psychology: dogs which despise the ordinary dog biscuits, seem quite satisfied with the same cheap foods when they are manufactured in the form of bones. The dog first plays with them and then eats them. There is no reason why everything should be left to mere tradition and chance in a field in which the methods are sufficiently developed to give exact practical results, as soon as distinct practical questions are raised. There would be no difficulty in measuring the reaction times of the horses in thousandths of a second for optical and acoustical and tactual impressions, or in studying the influence of artificial colour effects on the various insects in the service of agriculture.