Many people fail to grasp this point, apparently because they think of "scientific" evidence as only that produced in laboratories by controlled experiments. This leads them to treat field studies, however careful, thorough and well-documented, as "anecdotal"--mere preparation for the real thing, therefore properly ignored till it bears fruit entitled to be considered by learned persons. This attitude was much like that of cavalry generals in the First World War, waiting patiently for the infantry to clear the ground so that they could make the dashing charges that alone they thought entitled the name of warfare. Because these creatures are complex, only a tiny fraction of important truths about them can ever be seen in laboratories of expressed in control experiments. The same, of course, is true of the human race.