‎VAUCHER (J.P.)‎
‎Histoire des conferves d'eau douce contenant leurs différens modes de reproduction et la description de leurs principales espèces suivie de l'histoire des tremelles et des ulves d'eau douce -- EDITION ORIGINALE‎

‎Genève, Paschoud, 1803; un volume in 4 relié en demi-basane demi-basane à coins, dos orné de filets dorés (reliure de l'époque), (habile restauration à la coiffe, rousseurs), (2), 15pp., 285pp., 3pp., 17 planches,dorés‎

Reference : 5162

‎---- EDITION ORIGINALE ---- "VAUCHER'S MOST IMPORTANT WORK". (DSB) ---- "His observation and interpretation of conjugation and spore formation in algae, particularly in Ectosperma, was later renamed Vaucheria by De Candolle. Although the cell theory had not yet been developed, he drew and described the cells showing that they were bounded by separate walls and had a certain degree of independence. He showed how conjugation can occur between cells of threads lying side by side, or cells of a single thread folded over on itself, by means of the communication channel through which the contents of one cell pass to fuse with the contents of the other cell. He also showed male organs, or anthers, protruding to meet other cells and was sure that this was a sexual act, comparable to that found in higher plants and to the copulation of animals. The newly formed grains, or spores, dropped to the bottom of the ditches in which the algae were found, and in order to verify that they would germinate to give new filaments of Ectosperma in the spring he had to culture them in the laboratory, an uncommon practice at that time. He showed similar conjugation in other primitive algae, and the formation of new nets in old cells of Hydrodictyon". (DSB XIII p. 595)**5162/ARB4‎