39^ History of the Sexual Theory. [book hi. 



ments in Gardening' (17 17), I. p. 20). He planted twelve 

 tulips by themselves in a secluded part of his garden, and as 

 soon as they began to flower removed the anthers ; the result 

 was, that not one of them produced seeds, while four hundred 

 tulips in another part of the same garden produced seeds in 

 abundance. 



Twenty years pass by before another experiment is made. 

 James Logan 1 , Governor of Pennsylvania, an Irishman by 

 birth, set sonic plants of maize in each corner of a plot of 

 ground, which was forty feet broad, and about eighty long, and 

 experimented on them in various ways. In October he noted 

 the following results : — the cobs of the plants, from which he 

 had removed the male panicles when the stigmas were already 

 dependent, presented a good appearance ; but closer examina- 

 tion showed that they were unfertilised, with the exception of 

 one which was turned in the direction from which the wind 

 might have conveyed pollen from other plants. On the cobs, 

 from which he had removed some of the stigmas, he found 

 exactly as many grains as he had left stigmas. One cob, which 

 had been wrapped in muslin before the appearance of the 

 stigmas, produced only empty husks. 



Miller's experiments in 1751, which Koelreuter has extracted 

 from the ' Gardener's Dictionary,' part II 2 , are specially 

 interesting, because the aid of insects in pollination was then 

 observed for the first time. Miller planted twelve tulips, six 

 or seven ells apart, and carefully removed the stamens as soon 

 as the flowers began to open ; he imagined that he should thus 

 entirely prevent fertilisation ; some days after he saw some bees 



1 The account in the text is taken from Koelreuter's report in his ' Historie 

 der Versuche iiber das Geschlechte der Pflanzen,' as given at p. 188 of 

 Mikan's ' Opuscula Botanici Argumenti.' Logan's work, ' Experimenta et 

 Meletamata de Plantarum Generatione,' unknown to me, is said by Pritzel 

 to have been published at the Hague in 1739. Koelreuter cites from a 

 London edition of 1747. 



2 Koelreuter's report in Mikan's collection is again the authority which is 

 here relied on. 



