PART 1. | HISTORICAL INTRODUCTION. 29 
raised up Sprengel’s work too high, and have passed over in silence the flaw 
which explains why it remained inoperative for so many generations. Delpino! 
says in regard to the neglect of Sprengel,—and Severin Axell agrees with 
him: “It is sad to witness this war of error against truth, especially when 
the contest was begun by one who lived subsequently, and who, instead of 
profiting by the truths discovered by his predecessor, only set to work foolishly 
_ to deny them.” While fully acknowledging the justice of this opinion, I 
think that, to be fair to both sides, we must add: Sprengel’s discovery is an 
instructive example of how even work that is rich in acute observation and 
happy interpretations may remain inoperative if the idea at its foundation is 
defective. 
4, Darwin says in his paper on the fertilisation of Papilionaceous flowers 
by bees (p. 461) : “Andrew Knight many years ago propounded the doctrine 
that no plant self-fertilises itself for a perpetuity of generations. After pretty 
close investigation of the subject, I am strongly inclined to believe that this is 
a law of nature throughout the vegetable and animal kingdoms.” As Darwin 
also mentions, Knight had found by experiment in the case of the Pea 
that more numerous seeds and more vigorous offspring are obtained by the 
application of pollen from another flower than by self-fertilisation. 
1 Sull opera ‘* La distribuzione dei sesst, etc.” del Prof. F. Hildebrand, p. 10. 
