One of the difficulties which hinder the extended use of the nut-oil-cakes (palm kernel, coconut and ground-nut) is the prevalent impression that these cakes deteriorate rapidly on keeping. In recent articles dealing with these cakes frequent reference has been made to this point. Thus Voelcker (9) in his Annual Report for 1914 states that “one inconvenience attaching to palm-nut and coconut cakes is that they do not keep as well as linseed and cotton cakes and that there is a tendency for them to turn rancid.” In his Report for 1915, however, he says, “I have come across but few instances either with palm-nut cake or meal, in which these have been rancid or not in good condition.” Murray (8) states that manufacturers should realise that they still have to reassure farmers regarding the keeping qualities of palm kernel cake. In a later article in the Journal of the Board of Agriculture (3) it is stated that “palm-nut kernel cakes in the past have had the reputation of soon going rancid…. At the present day, before the kernels are crushed they are subjected to a process of cooking, by which the ferment that causes the oil to turn rancid is rendered inactive.” The validity of this latter assertion seems doubtful in the light of the recent work of Calder (2) which shows that the lipase, present in the resting seed in the form of its zymogen, is not destroyed during the manufacture of the cake, the mass of crushed kernels not being sufficiently heated in every part prior to pressing to secure this object completely. Similar statements have been made as to the liability of coconut and ground-nut cakes to become rancid on storing (3,4).