Original edition of this milestone in the history of biology. Sprengel’s remarkable work was quite forgotten for half a century until Darwin brought it again before the scientific world and showed its important bearing of the theory of descent. Sprengel‘s case was analogous to that of Mendel, whose Versuche über Pflanzenhybriden (1865) remained unnoticed for 35 years. Mendel’s paper and Sprengel’s book are both of legendary rarity. Sprengel was rector and teacher at Spandau. There in 1787 he became fascinated by the process of pollination when he noticed hairs on the petals of Geranium flowers. For the next six years he devoted himself with complete absorbation to examining and recording the relations between flowers and their pollinating insects. In 1793 he published his book, which was quite revolutionary. "Sprengel perceived for the first time, and described in accurate detail, all the principle adaptive floral mechanisms concerned with pollination; and he illustrated them by over a thousand engraved figures for which he did the drawings himself. The step-by-step account of how he reached his conclusions, and his descriptions of the structure of individual flowers, still make fascinating and profitable reading” (Morton). He noted that colour and scent are attractions, that the corolla markings are guides to the hidden nectar, and that grasses have light pollen and are wind-pollinated. The book was a complete failure for Sprengel and he was greatly disappointed with the reception of the book. His work received such scant attention that he gave up his botanical pursuits. The significance of his conclusions went beyond the comprehension of botanists at the time; even his facts awakened little interests. He was also removed from his post at Spandau because he devoted too much time for botany and neglected his duties as a teacher. He afterwards lived a solitary life in straitened circumstances in Berlin, being shunned by men of science as a strange, eccentric person. He met with so little support that he never brought out the second part of his work; his publisher did not even give him a copy of the first part. Sprengel did not marry and died in 1816 in relative obscurity. No notice about his death has been found. Collation: Engraved title-leaf, 444 columns, (4) leaves. With 25 engraved plates printed on fine blue paper, while the text is printed on rather poor paper. Contemporary half calf, marbled boards, red edges. Printed in double columns with 25 exquisite copperplates crowded (out of economical reasons) with 1117 drawings of floral parts representing 416 species. The striking title-page also serves as a plate since the wide border comprises of 28 insects and flower drawings composed by the author. References: Dibner, Heralds of Science, 30; Sparrow, Milestones of Science, 184; Junk Rara 63; Sachs, History of Botany, 414-22; Morton, History of Botanical Science, 326-28; DSB, XII, 587-91. The importance and inaccessibility of Sprengel’s book may be illustrated by the fact that a facsimile appeared in 1893, and that the work was reprinted in Ostwald’s Klassiker. Waller 11738.