Chapter Summary. In this chapter, we turn to Aristotle’s inquiry into the formation of uniform bodies in Mete. iv and explore the ways in which the investigations reported in PA ii and GA ii and v are dependent on it. Aristotle often insists on the paramount importance for natural inquiry of searching for ends as causes of natural processes, and thus of teleological explanations in understanding the natural world. Yet, as we are about to see, in Mete. iv he develops independent, material-level explanations of the formation of uniform bodies, including the uniform parts of animals. Looking carefully at this text will thus further our understanding of the normative constraints on inquiry into nature. What are the limits on material and teleological explanation in an Aristotelian science of nature? Moreover, looking at the interplay between Mete. iv and the biological study of the coming to be and being of uniform parts provides a second rich case study by which to explore the nature of the dependence of one natural inquiry on the results of another.