中文摘要：

食土行为是指动物有选择性的摄取土壤的过程。许多灵长类动物都表现出了食土行为。研究表明，这种行为的普遍存在可能与其在营养平衡、健康调节方面所起的重要作用密切相关。本文搜集整理了大量灵长类动物食土行为的资料，归纳了解释此行为的六种假说，对其作初步的解释，并提出一些实验方案来揭示食土行为的功能。其中四种假说认为食土行为能够缓解肠胃功能的紊乱；两种假说是关于食土行为能够补充矿物质或矿物元素。此外，灵长类动物的食土行为或许能够满足嗅觉神经的需求，也许只是食物极度匮乏时为了充饥才选择的食物，也可能根本没有任何的作用。我们归纳矿物质补充、吸附毒素、治疗腹泻和调节肠胃pH值是灵长类动物养成食土行为较为合理的原因。

英文摘要：

Geophagy,or soil ingestion,is a selective behavior to consume soil.This behavior is widespread in animal,especially in primates.This behavior is presumed to be important to health and nutrition.Here we present,and draw together sufficient information from various sources to assess some possible hypotheses,and suggest some tests to understand the founction of geophagy.Four hypotheses relate to alleviate gastrointestinal disorders or upsets.On the other hand,it is supposed to supplement minerals and/or elements.It may also serve as a famine food,satiate sensory organs or may have no significance other than mere behavioural tradition.We conclude that minerals supplementation,adsorbption of toxins,treatment of diarrhoea and pH adjustment of the gut seem the most possible reasons for primates to engage in geophagy.