Note 1 — Chapter XIX · SUMMARY OF THE FOUR LAST CHAPTERS, WITH REMARKS ON HYBRIDISM.

‘Transactions Phil. Soc.,’ 1799, p. 202. For Kölreuter see ‘Mém. de l’Acad. de St.-Pétersbourg,’ tom. iii. 1809 (published 1811) p. 197. In reading C. K. Sprengel’s remarkable work, ‘Das entdeckte Geheimniss,’ etc., 1793, it is curious to observe how often this wonderfully acute observer failed to understand the full meaning of the structure of the flowers which he has so well described, from not always having before his mind the key to the problem, namely, the good derived from the crossing of distinct individual plants.