Abstract: I BECAME acquainted with Christian Conrad Sprengel's work, “Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen” (Berlin, 1793) in 1850 at the University of Berlin through Prof. C. H. Schultz-Schulzenstein, who brought it forward in one of his lectures on botany, praising Sprengel's good observations and illustrations, but making his teleological views appear so irksome as to dispose his hearers rather to depreciate and reject the book than be attracted to it by respect. The value of Sprengel's treatise in its bearing on the theory of selection was first recognised by Charles Darwin, whose writings recalled the remarkable book to my mind, and induced me to buy it, which I did at a very cheap rate at an old book-shop.