82 CLASSICS OF MODERN SCIENCE 

 flowers of another, and have always found the seeds of the latter 

 impregnated by it. 



Two years ago I placed a piece of paper under some of these male 

 flowers and afterwards folded up the pollen which had fallen 

 upon it, preserving it so folded up, if I remember right, four or 

 six weeks, at the end of which time another branch of the same 

 Jatropha was in flower. I then took the pollen, which I had so long 

 preserved in paper, and strewed it over three female flowers, the 

 only ones at that time expanded. The three females proved 

 fruitful, while all the rest, which grew in the same bunch, fell oft* 

 abortive. 



The interior petals of the Ornithogalum, commonly but improperly 

 called Canadense, cohere so closely together that they only just 

 admit the air to the germen and will scarcely permit the pollen of 

 another flower to pass; this plant produced every day new flowers 

 and fruit, the fructification never failing in any instance ; I therefore, 

 with the utmost care, extracted the antherae from one of the flowers 

 with a hooked needle, and as I hoped, this single flower proved 

 barren. This experiment was repeated about a week after with the 

 same success. 



I removed all of the antherae out of a flower of Chelidonium coniic- 

 ulatum (scarlet -horned poppy), which was growing in a remote part 

 of the garden, upon the first opening of its petals, and stripped off 

 all the rest of the flowers ; another day I treated another flower of the 

 same plant in a similar manner, but sprinkled the pistillum of this 

 with the pollen borrowed from another plant of the same species ; 

 the result was, that the first flower produced no fruit, but the second 

 afforded very perfect seed. My design in this experiment was to 

 prove that the mere removal of the antherae from a flower is not in 

 itself suflicient to render the germen abortive. 



Having the Nicotiana fruticosa growing in a garden-pot, and pro- 

 ducing plenty of flowers and seed, I extracted the antherae from the 

 newly expanded flowers before they had burst, at the same time cut- 

 ting away all the other flowers; this germen produced no fruit, nor 

 did it even swell. 



I removed an urn, in which the Asphodelus fistiilosus was grow- 

 ing, to one corner of the garden, and from one of the flowers which 

 had lately opened, I extracted its antherae ; this caused the impregna- 



