Animal and Machine
动物与机器
The body of an animal may well be compared with some machine like a locomotive engine. Indeed, the animal body is a machine. It is a machine composed of many parts, each part doing some particular kind of work for which a particular kind of structure fits it; and all the parts are dependent on each other and work together for the accomplishment of the total business of the machine. The locomotive must be provided with fuel, such as coal or wood or other combustible substance, the consumption of which furnishes the force or energy of the machine. The animal body must be provided with fuel, which is called food, which furnished similarly the energy of the animal. Oxygen must be provided for the combustion of the fuel in the locomotive and of the food in the body. The locomotive is composed of special parts: the fire box for the reception and combustion of fuel; the steam pipes for the carriage of steam; the wheels for locomotion; the smokestack for throwing off waste. The animal body is similarly composed of parts: the alimentary canal for the reception and assimilation of food; the excretory organs for the throwing off of waste matter; the arteries and veins for the carriage oxygen and food-holding blood; the legs or wings for locomotion.
动物的身体很可以与某种机器如火车头相比。实际上，动物的身体就是一台机器。它是一台由许多部件组成的机器。每个部件起某种特定的作用，并具有特殊构造使它适合于这种作用，所有的部件互相依赖、彼此合作，以完成机器的整个任务。火车头必须添加燃料，如煤，木柴或其他可燃物质。燃料的消耗给机器提供动力或能量。动物的身体也得补充燃料，它被称为食物，给动物同样地提供能量。为使火车头里的燃料燃烧以及动物体内的食物氧化，必须提供氧气。火车头是由特殊部件构成的;接受并燃烧燃料的炉膛、运送蒸气的管道，使车头运行的轮子及排出废气的烟囱。与此相似，动物的身体也是由各种部件构成的：摄入并吸收食物的消化道、排出废物的排泄器官以及运送氧气和保存养料的血液的动脉与静脉，还有使动物行进的腿或翅膀。
