1. A partial hydrolysis of 14C-labelled tripalmitin has been demonstrated in the crop of Periplaneta americana L.
2. No significant absorption of tripalmitin and its derivatives could be demonstrated in the crop, whether the tripalmitin was suspended in an experimental fluid or dissolved in emulsified oleic acid.
3. Absorption took place in the mid-gut and appeared to be largely confined to the caeca and the anterior part of the ventriculus.
4. The total absorption of tripalmitin showed a linear relation with crop emptying, suggesting that the rate at which the material was allowed to leave the crop, rather than the uptake in the mid-gut, was the limiting factor in absorption.