Harvey's treatise on generation is clearly a product of his time. It advances embryology by its demonstration of certain facts of development, by its aggressive espousal of epigenesis and the origin of all animals from eggs, and by its dynamic approach stressing the temporal factors in development and the initial independent function of embryonic organs. However, the strong Aristotelian cast of Harvey's treatise encouraged continued discussion of long outdated questions in an outdated manner and, combined with his expressed disdain for "chymistry" and atomism, discouraged close cooperation between embryologists of different persuasions. It is perhaps easy to underestimate the impact and general importance of Harvey's work in view of these qualifications, and so it should be remarked that both positive and negative features of _De Generatione_ influenced profoundly subsequent embryological thought. It will be recalled that the title of _The Philosophicall Touch-Stone_ identified Digby as the object of Alexander Ross's ire. In comparable manner, the latter's _Arcana Microcosmi_, published in 1652, declares its purpose to be "a refutation of Dr. Brown's Vulgar Errors, the Lord Bacon's Natural History, and Dr. Harvy's book _De Generatione_." Let us pause a brief moment in memory of a man so intrepid as to undertake the refutation of three of England's great intellects in one small volume, and then proceed to examine the embryological concepts of one of the trio, Sir Thomas Browne. Browne's _Religio Medici_, composed as a private confession of faith around 1635, is known to all students of English literature, as is his later, splendid work on death and immortality, _Hydrotaphia, Urne-Buriall_. One of the greatest stylists of English prose, Browne was also a physician and a student of generation who deserves our attention as an early chemical embryologist pointing the way to a form of embryological investigation prominent in the last half of the seventeenth century. Browne's embryological opinions are found particularly in _Pseudodoxia Epidemica_, _The Garden of Cyrus_, and in his unpublished _Miscellaneous Writings_. Browne, a well-read man, was educated at Oxford, Montpellier, Padua, and Leyden, and he was thoroughly imbued with the teaching of the prophets of the "new learning." This is evident throughout his writings, as witness his admonition to the reader of the _Christian Morals_: Let thy Studies be free as thy Thoughts and Contemplations, but fly not only upon the wings of Imagination; Joyn Sense unto Reason, and Experiment unto Speculation, and so give life unto Embryon Truths, and Verities yet in their Chaos.[26]