See Stirling’s Oct 25 journal entry, in which Stirling associates the custom with marriage. The custom of cutting off joints of fingers during times of mourning for the recently deceased has been widely reported from highland western New Guinea. See photographs in Plate LXXX, vol. 3 of De Bergpapoea’s van Nieuw-Guinea en hun woongebied by C.C.F.M. le Roux (Leiden: E.J. Brill, 1950). Also see illustration of Dani woman in mourning, for example, in Hampton’s Culture of Stone: Sacred and Profane Uses of Sone among the Dani (College Station: Texas A&M University Press, 1999) plate 2 and fig. 1.15 on p. 22; and discussion, pp. 21-22. More discussion of this practice is in Gardner and Heider’s Gardens of War: Life and Death in the New Guinea Stone Age (New York: Random House, 1968), p. 96.