Dubois was bitter about this and locked the fossil up in a trunk until 1923 when he showed it to Ales Hrdlicka from the Smithsonian Institution. In response to critics who refused to accept that Java Man was a "missing link", in 1932 Dubois published a paper arguing that the Trinil bones looked like those of a "giant gibbon". Dubois's use of the phrase has been widely misinterpreted as a retraction, but it was intended an argument to support his claim that "Pithecanthropus" was a transitional form. According to Dubois, evolution occurred by leaps, and the ancestors of humanity had doubled their brain-to-body ratio on each leap. To prove that Java Man was the "missing link" between apes and humans, he therefore had to show that its brain-to-body ratio was double that of apes and half that of humans. The problem was that Java Man's cranial capacity was 900 cubic centimeters, about two-thirds of modern humans'.