A translation from the German edition, G. Hatje, Stuttgart, 1957. The catalogue lists 147 sculptures created between 1930 and 1957. The documentation was provided by Marguerite Hagenbach, the artist's second wife. For further reference on the later work, see also: "Jean Arp Sculpture : His Last Ten Years", which continues the catalogue of Arp's sculpture, listing works numbered 148 - 371.