Many organisms in the visible world were also poorly served by the traditional division. Fungi, the group that includes mushrooms, molds, mildews, yeasts, and puffballs, were nearly always treated as botanical objects, though in fact almost nothing about them—how they reproduce and respire, how they build themselves—matches anything in the plant world. Structurally they have more in common with animals in that they build their cells from chitin, a material that gives them their distinctive texture. The same substance is used to make the shells of insects and the claws of mammals, though it isn't nearly so tasty in a stag beetle as in a Portobello mushroom. Above all, unlike all plants, fungi don't photosynthesize, so they have no chlorophyll and thus are not green. Instead they grow directly on their food source, which can be almost anything. Fungi will eat the sulfur off a concrete wall or the decaying matter between your toes—two things no plant will do. Almost the only plantlike quality they have is that they root.
传统的分类法也不大适用于可见世界里的许多微生物。真菌这个群涵盖了蘑菇、霉、霉菌、酵母和马勃菌，几乎总是被看做是植物体，而实际上，它们身上几乎没有任何特点——它们的繁殖方式、呼吸方式、成长方式——是与植物界相吻合的。从结构上说，它们与动物有着更多的共同点，因为它们是几丁质构建自己的细胞的。那种材料使用其质地与众不同。昆虫的外壳和哺乳动物的爪子都是由那种材料构成的，虽然鹿角锹甲的味道远不如蘑菇那么鲜美。尤其，真菌不像所有的植物那样会产生光合作用，所以它们没有叶绿素，因此不是绿色的。恰恰相反，它们是直接吃东西长大的。它们几乎什么东西都吃。真菌会侵蚀混凝土墙上的硫或你脚趾间的腐败物质——这两件事植物都干不了。它们差不多只有一种植物特性，那就是它们有根。

Even less comfortably susceptible to categorization was the peculiar group of organisms formally called myxomycetes but more commonly known as slime molds. The name no doubt has much to do with their obscurity. An appellation that sounded a little more dynamic— "ambulant self-activating protoplasm," say—and less like the stuff you find when you reach deep into a clogged drain would almost certainly have earned these extraordinary entities a more immediate share of the attention they deserve, for slime molds are, make no mistake, among the most interesting organisms in nature.
那种分类法更不适用于一种特殊的微生物群，那种微生物过去被叫做黏菌，现在更常常被称之为黏性杆菌。它们的默默无闻无疑与这个名字有关。要是那个名字听上去更有活力——比如，“流动自我激活原生质”——而不大像是你把手伸到阴沟深处会发现的那种东西，那种非同寻常的实体几乎肯定会马上受到应该受到的那份重视，因为黏性杆菌无疑属于自然界最有意思的微生物。