Chap. VII. POLYGAMOUS PLANTS. 291 



fruit. I then took by hazard 15 fruit from an adjoin- 

 ing female bush, and these contained 43 seeds; that 

 is more than twice as many, or on an average 2.86 

 per fruit. Many of the fruits from the female bushes 



* 



included four seeds, and only one had a single seed; 

 whereas not one fruit from the polleniferous bushes 

 contained four seeds. Moreover, when the two lots of 

 seeds were compared, it was manifest that those from 

 the female bushes were the larger. The second pollen- 

 iferous bush, D, bore in 1863 about two dozen fruit,- 

 in 1864 only 3 very poor fruit, each containing a single 

 seed, — and in 1865, 20 equally poor fruit. Lastly, the 

 three polleniferous bushes, E, F, and G, did not pro- 

 duce a single fruit during the three years 1863, 1864, 

 and 1865. 



"We thus see that the female bushes differ somewhat 

 in their degree of fertility, and the polleniferous ones 

 in the most marked manner. We have a perfect grada- 

 tion from the female bush, B, which in 1865 was covered 

 with "innumerable fruit," — through the female A, 

 which produced during the same year 97, — through the 

 polleniferous bush C, which produced this year 92 fruits, 

 these, however, containing a very low average number of 

 seeds of small size, — through the bush D, which pro- 

 duced only 20 poor fruit, — to the three bushes, E, F, 

 and G, which did not this year, or during the two pre- 

 vious years, produce a single fruit. If these latter 

 bushes and the more fertile female ones were to supplant 

 the others, the spindle-tree would- be as strictly dioecious 

 in function as any plant in the world. This case appears 

 to me very interesting, as showing how gradually an her- 

 maphrodite plant may be converted into a dioecious one.* 



* According to Fritz Mfiller Southern Brazil is in nearly the 

 CBot. Zeitung,' 1870, p. 151), a same state as our Euonymus. The 

 Chamissoa (Amaranthacese) in ovules are equally developed in 



