Arp began making free-standing sculpture in the early 1930s. His sensuous, 'abstract' works changed little in style from that time to the 1960s. Arp called his sculptures 'human concretions', a term chosen to suggest that they might have grown out of the human body. He did not consider these works as abstract, but rather as organic forms which had occurred naturally. The vertical nature of this sculpture suggests parallels with the human form: Arp made a number of vertical works from the mid-1950s to the 1960s.