PLANT HYBRIDIZATION BEFORE MENDEL 73 



it evident that the greater part of the difficulties which the botanists 

 make a display of in their theories, which very often they invent, in 

 relation to the fecundation of vegetables, have almost no reality, and, 

 if they had, it would necessarily require that the greater number of 

 plants remained sterile." (p. 108.) 



A third experiment in the fertilization of the palm, was again 

 undertaken in 1767. The species of palm used in the experiments 

 was, according to Gleditsch's statement, the same individual as 

 used in the two previous ones. (p. 7.) 



"The female palm which we preserve in the Royal Botanical Garden is 

 very old, and of fine appearance, without having ever borne dates up to 

 the years 1749 and 1750, when I fertilized it for the first and second 

 times with the powder of the flowers which I had let come from Leipzig 

 by post. I made report at the same time to the Academy of these two 

 experiments, and I produced by means of the dates, perfectly ripe, young 

 palms, which exist still in the garden." (p. 7.) 



After describing the pollination of the palm by means of the 

 transportation of the pollen by air currents, and the hand- 

 pollination of the date in oriental countries, which, he says, 

 "has taken place in these countries since men inhabit them and 

 cultivate them," he remarks: 



"This does not prevent the savants from putting the question nowa- 

 days of whether the thing is possible, and the fact is real." (p. 6.) 



"Let one separate the male palms from these female ones," he con- 

 tinues, "of which I have said above that the proximity of the males was 

 absolutely necessary for them for fertilization ; one will infallibly see 

 happen what took place at Berlin with respect to our female palm, since 

 the time of the late King Frederick I, to wit, that this tree, deprived of 

 its male, had remained in perfect sterility since, and that its fruits have 

 not reached maturity." (p. 6.) 



"No one indeed," he says, "will ever confound the unfertilized debris 

 which our palm produced, every year, and which I place here by the side 

 of the effect of fecundation, with these perfect fruits, and especially with 

 that which has served to produce a young palm which derives its extrac- 

 tion from the first." (p. 7.) 



The pollen for the third pollination experiments was sent from 

 Karlsruhe, a distance of eighty miles. Referring to the custom in 

 the orient, of hunting for the male trees, from which the inhabi- 

 tants bring in clusters of the staminate flowers to hang beside 

 the female flowers, he makes the statement that the male flowers 

 remain sometimes fifteen days or three weeks on the road before 

 being used for pollination. 



Before undertaking the first two experiments in fertilizing the 

 palm, Gleditsch states that he made other preliminary ones in the 



