published them, together with some similar works of Koelreuter,
at Prague in 1797 under the title, 'R. J. Camerarii Opuscula Botanici Argument!.' This book, apparently little known, will
be my principal authority for the following remarks. The
short preliminary communications are printed without alteration
from the ninth and tenth year of the second, and from the fifth
and sixth year of the third decury of the Ephemerides of the
Leopoldina; the letter to Valentin, which will be noticed
again further on, together with an abstract of the same and an
answer of Valentin, are given according to Gmelin's edition of 1749.
Camerarius had observed, that a female mulberry-tree once bore fruit, though no male tree (amentaceis floribus) was in its neighbourhood, but that the berries contained only abortive and empty seeds, which he compared to the addled eggs of a bird. His attention was roused, and he made his first experiment on another dioecious plant, Mercurialis annua; he took in the end of May two female specimens of the wild plant (they were usually called male, but he knew them t'o be the female) and set them in pots apart from others. The plants throve, the fruit was abundant and filled out, but when half ripe they began to dry up, and not one produced perfect seeds; his communication on this subject is dated December 28, 1691. In the third decury of the Ephemerides, year 5, he relates that in a sowing of spinach he had found monoecious as well as dioecious plants, as Ray had observed in Urtica romana, and he himself again in three other species. The disregard of this fact was afterwards the cause of erroneous interpretation of the experiments and of doubt about sexuality.
and finally, in 1695, First Professor of the University, in succession to his father, Elias Rudolph Camerarius. He was afterwards succeeded by his son Alexander, one of ten children. There is an article on Camerarius in the 'Biographic Universelle,' from the pen of Du Petit-Thouars. His works on other subjects, as well as those on the question of sexuality in plants, are distinguished by ingenious conception and lucid exposition.
