CHAP. III. 



ERYTHROXYLUM. 



121 



what opposed to the present species being heterostyled ; as is 

 the great difference in the length of the pistil in several short- 

 styled flowers. But the extraordinary variability in diameter of 

 the pollen-grains, and the fact that in one set of flowers the 

 grains from the long-styled flowers were larger than those from 

 the short-styled, is strongly opposed to the belief that Phlox 

 subulata is heterostyled. Possibly this species was once hetero- 

 styled, but is now becoming sub-dioecious; the short-styled 

 plants having been rendered more feminine in nature. This 

 would account for their ovaries usually containing more ovules, 

 and for the variable condition of their pollen-grains. Whether 

 the long-styled plants are now changing their nature, as would 

 appear to be the case from the variability of their pollen-grains, 

 and are becoming more masculine, I will not pretend to con- 

 jecture; they might remain as hermaphrodites, for the co- 

 existence of hermaphrodite and female plants of the same 

 species is by no means a rare event. 



ERYTHROXYLUM [SP. ?] (ERYTHROXYLIDJE). 



Fritz Miiller sent me from South Brazil dried flowers of this 

 tree, together. with the accompanying drawings, which show the 

 two forms, magnified about five times, with the petals removed 



Losg-styled form. Short-style.! form. 



From a sketch by Fritz Miillcr, magnified five noses. 

 EBYTHKOXYLON [sp. ?]. 





