placed in contact with a female flower recently open, and tied this flower with a piece of red 



silk to know it again. 



The next day I removed the male flower, and this one germen indeed remained, and pro- 

 duced fruit. 



After the experiment, I took another male flower from the stove, and by means of a slender 

 forceps, I removed from it one of its Anthers, and having scratched it gently with the knib of a 

 pen, I took care that a little of its farina might fall upon one of the Stigma, having guarded the 

 remaining two stigmata by a cap made by an hollow roll of paper. 



This Germen also grew to a fruit of the ordinary size, and afterwards being transversely 

 dissected, it alone produced a large seed in one of the three cells, the other two being empty. 



The other flowers, not having suffered impregnation, every one of them, becoming withered, 



dropt. 



The repetition of this experiment is also as readily to be repeated as the former. 



FOURTH AND FIFTH EXPERIMENTS. 



The Jatropha Urens (Stinging Jatropha) flowers every year in my hot-house, but the 

 female flowers have preceded the males, and before eight clays they lost their petals, and faded, 

 before the male flowers were expanded. 



Hence not only they produced no fruit, but the flowers themselves dropt. 

 Thus it happened that, until the year 1752, we could obtain no fruit of the Jatropha. 



But in this year, the male flowers were in vigour upon a taller tree, at the precise time the 

 females appeared on a small Jatropha growing in a pot. 



This pot I placed under the tree producing male flowers, and in this manner I accomplished,, 

 that the female flowers produced seed, which, being sown in the earth, grew. 



Two years after I placed these male flowers under a piece of paper, until the Farina had 

 fallen upon it, which I preserved rolled up, if I recollect right, for four or five weeks, when 

 this same Jatropha on another branch produced female flowers. 



Then I sprinkled that Farina so long preserved in paper upon three flowers, the only ones at 



that time expanded. 



These three female flowers only became fruitful, whereas all the other floxvers which appeared 



hi the same corymbus fell off abortive* 



I have frequently since amused myself by taking the male Farina from one plant, which 

 by sprinkling upon the females of another, I have always found the seeds thereby rendered 

 fruitful.t 



* The same experiment was made on the J.troph. Im««.l» {Imperial Jatropha) and with exaetly the same result. The male 

 flowerslaHyoccupy the upper part of the plant, and are soon to he distingmshed from ^females. 



+ AsimU, experiment was m,^^^ 

 £Si£t eo^n" ^KS-Sff wh^ L same —on of the Sexual Hypothesis. 



n SIXTH 



