When I met my cat Pearlita， she lived in an alley between my apartment building and a gas station. She drank from puddles polluted by engine leaks and ate whatever she could find. Ten years later， with Pearlita curled up on my lap， making it hard to type， I can still remember how she wolfed down the food I put in the alley and how easy it was to lure her inside with more.

我是在公寓楼和加油站间的一条小巷里遇见我的爱猫小珍珠的。她喝那些因机油泄露而被污染的水坑里的水，能找到什么就吃什么。10年后，小珍珠蜷缩在我的大腿上，我几乎无法敲字，但我仍记得她曾如何狼吞虎咽掉我放在巷子里的食物，我又曾怎样轻易地用更多吃食将她诱入家门。

But does she remember her life on the streets？ And if so， which parts of it？

但她是否还记得自己在街边流浪的生活？如果记得，记住的又是其中哪些过往？

This question has probably occurred to almost anyone with an animal friend， but for simplicity’s sake， we’ll limit this discussion to our feline and canine companions. Certainly they behave as though they have memories—after all， your special furball doesn’t treat you like a stranger each time you walk through the door—and evolutionary theory suggests as much： It behooves any long-lived animal to have long-lasting recollections. There have been rigorous scientific experiments， too， not enough to fully understand our dogs’ and cats’ memories， but enough to confirm their existence and to raise some interesting questions about how they compare to our own.

几乎所有与动物为友的人都可能有过此类疑问，但简单起见，我们这次的讨论仅限于陪伴我们的猫和狗。当然，它们表现得就像是有记忆——毕竟，你的毛孩子不会在你每次进门时都当你是陌生人——而且进化理论也如此说明：任何长寿的动物都应当具备长期记忆。