From a cross of two short peas an aberrant type was obtained in F2. Plants of this type emerged from the soil in a strongly bent condition and reminded one by their further growth of etiolated, rapidly growing plants with little chlorophyll and weakly developed stipules and leaves. The rapid growth continued and resulted in very long, unbranched plants of a slender built which reached a length of 3–3.76 m. The flowerstalks were exceptionally long, the flowers of an aberrant type, caused by non-coalescence of the two parts of the keel. A considerable number of pods were parthenocarp, some produced a decreased number of seeds; pods with the normal number of seeds were scarce. This new form was called “slender” and it was shown that the characters mentioned, were caused by the pleiotrope action of two multiple factors (la and lb), both occurring recessively in the slender plants. The independent transmission of the factors La, Lb and Le could be demonstrated, the existence of linkage between lb and walso.