On the habit, ecology and taxonomy of the brambles of the Netherlands. 1. The connection between mode of life and taxonomic position of our Rubus species is discussed. The importance of the influence of environmental and heriditary factors on the habit and development of the plant is pointed out. 2. A knowledge of the mode of life and the behaviour of the plants in definite ecological conditions is of importance for recognizing the species in the field. A survey is given of the principal ecological data. 3. The various modes of multiplication are summarized, since they lead to a better understanding of the species and of the ecological forms mentioned above. 4. In conclusion the classification proposed for the genus Rubus by Focke and by Sudre are reproduced and compared.