HISTORICAL DEVELOPMENT OF FLOWER POLLINATION 3 



(Epilobium, Linn. Sp. PI., p. 347, notes i and 2) open before any of the anthers yield 

 their pollen, before the pistil, which is curved downwards under the flower begins 

 to raise itself, and while the four stigmas still lie close together, before curving 

 outwards and separating from one another, so as to expose their inner surfaces 

 beset with little warts. ... In the later flowers of this plant, pollination is effected 

 entirely by insects, for the anthers open long before the stigmas become erect 

 and spread out. Meanwhile, either the pollen is wasted on the anthers, or it is 

 carried away by insects. So the stigmas remain without pollen, and no fertilization 

 could occur unless insects were to bring fresh pollen from other flowers.' In 

 connection with these observations, Kolreuter then dwells anew upon the importance 

 of insects in fertilization : ' In general, plants in which pollination is not regularly 

 effected by direct contact have the help of insects in effecting pollination, and 

 consequently also fertilization. Probably the insects perform this very great service, 

 if not for the majority of plants, at least for a very great number of them ; since 

 almost all such flowers as I refer to have something about them that is agreeable to 

 insects, and it is not easy to find one about which these creatures do not swarm.' 



If Kolreuter is to be regarded as the founder of flower pollination, we meet in 

 Christian Konrad Sprengel ^ with a man who raised this branch of botany to a very 

 high level, as he not only made clear the essential ideas of the theory of flowers, but 

 also recorded an abundance of details with the most admirable acuteness. His work, 

 ' Das entdeckte Geheimniss der Natur im Bau und in der Befruchtung der Blumen ' 

 (Berlin, 1793, 4to), contains a description of floral adaptations in nearly 500 species 

 of plants. Many of these are described in great detail, and with such accuracy 

 that hardly anything can now be added, except information as to the visitors, 

 with their scientific names; for Sprengel was an excellent botanist, but knew 

 little about insects. 



Seeing that Sprengel is so prominent in the history of flower pollination, it 

 appears appropriate to give in his own words part of the introduction to his 

 book. He begins as follows. 



'In the summer of 1787, while I carefully watched the flower of the wild 

 geranium {Geranium sylvaiicuni), I found that the bases of its petals were provided 

 on the inner side and on both edges with fine soft hairs. Convinced that the 

 wise Creator of nature has brought forth not even a single hair without some 

 particular design, I considered what purpose these hairs might serve. And here 

 it occurred to me that if one starts with the supposition that the five drops of 

 nectar, which are secreted from as many glands, are destined for the nourishment 



' Christian K. Sprengel was born in 1750 at Brandenburg, and was the son of a clergyman. 

 He studied theology and philology, and in 1774 became teacher at the school of the great 

 Friedrichs-Hospital in Berlin. At the same time he gave instruction at the Royal Acole Militaire. 

 In 1780 he became Rector at the great Lutheran School (the present Gymnasium) at Spandau. 

 In 1794, after long struggles with his unfriendly superior, the Inspector-Superintendent Schulze, 

 he was pensioned and retired to Berlin, where he died in complete seclusion on April 7, 18 16. 

 Further details as to the life of this great investigator occur in the following essays in the 

 ' Naturwissenschaftliche Wochenschrift,' viii (1893): 'Christian Konrad Sprengel, der Begriinder 

 der modernen Blumentheorie,' by O. Kirchner (Nos. 11 and 12), and ' Material zu einer Biographic 

 Christian Konrad Sprengels,' by R. Mittmann (Nos. 13, 14, and 15). 



B 2 



