During millions of years of evolution2, ants have developed intriguing3 relationships with many different kinds of plants.Most of these associations4 are loose ones -- the ants find dwelling5 places on the plants,while bringing neither harm nor benefit to them. Often the ants live in hollow dead stems or small pockets of soil that accumulate6 on branches. Thus ants inhabit trees over our heads and herbs at our feet,carving out living chambers7 and foraging8 for food. As many as 72 different species of ants have been found living on one tree in Perus Amazon Basin alone.
　　However, in some relationships between ants and plants both sides give and get. The plants in such mutualistic partnerships are called ant-plants. Many of them are beautiful examples of coevolution, having adapted9 together with their ant partners to thrive in nutrient-poor areas.
　　In ant-plant relationships ants provide nutrients,protection, and housekeeping to plants. Plants provide food and shelter10 to ants.Some ants in these types of relationships serve their hosts as devoted sentinels11,repelling12 or killing unwelcome intruders13 such as beetles and caterpillars14. Others fertilize their hosts with waste from the food they drag home to eat. In return, many plants have evolved special structures to house and feed ant colonies, including leaves with hollow cavities15 and seeds with edible coatings or attachments. Frequently plants and ants become so dependent on one another that they cannot live apart.
　　
　　
　　 注释：
　　1．profitable adj．有益的，有用的
　　2．evolution n．[生]进化，进化论
　　3．intriguing adj．引起好奇心(或兴趣的)，有迷惑力的
　　4．association n．友谊，伙伴关系
　　5．dwelling n．住处，住宅，寓所
　　6．accumulatevt．堆积，积聚
　　7．chambern．室，寝室
　　8．forage vi．搜寻
　　9．adapt vi．适应
　　10．shelter n．[美]动物的栖息处11．sentineln. 步哨，哨兵
　　12．reple vt．击退，逐回，驱除13．intrudern．侵入者，闯入者
　　14．caterpillarn．[昆]毛虫 (鳞翅目昆虫如蝶、蛾等的幼虫)
　　15．cavityn．洞，穴，凹处
　　
　　经过几百万年的进化，蚂蚁与多种不同植物形成了十分有趣的关系。其中大多数关系并不紧密：蚂蚁在植物上寻找居所，而并不给植物带来利和害。蚂蚁经常栖于中空的植物枯茎或枝干上堆积的小土坑中。因此，我们头顶的树木和脚下的草丛中都住着蚂蚁，它们在那儿建造居室或搜寻食物。仅在秘鲁的亚马逊流域，一棵树上住的蚁类就达72种之多。
　　但是，蚂蚁与植物之间有些关系则是双方互利的。这种互利共生关系中的植物称为“蚁居植物”。大多数这种植物都是共同进化的完美样本，它们与其蚂蚁伙伴共同适应了养分匮乏的地区以求生存。
　　在蚂蚁与植物的共生关系中，蚂蚁负责为植物提供养分、保卫及清洁工作；植物则为蚂蚁提供食物和居所。这种共生关系中的有些蚁类还为其宿主担任忠实的哨兵，驱赶或杀死诸如甲虫和毛虫等这些不速之客。其他蚁类把拖回去的食物吃完后排出的粪便可给宿主提供养分。作为对蚁类的回报，许多植物都进化出独特的结构，如有空穴的叶片和外皮或其他部分可食的种子供蚂蚁居民住和吃。蚂蚁和植物时常会因彼此太过依赖而无法各自生存。