38 HETEROSTYLED DIMORPHIC PLANTS. CHAP. I. 



PRIMULA SINENSIS. 



In the long-styled form the pistil is about twice as 

 long as that of the short-styled, and the stamens differ 

 in a corresponding, but reversed, manner. The stigma 

 is considerably more elongated and rougher than that 

 of the short-styled, which is smooth and almost 

 spherical, being somewhat depressed on the summit; 

 but the stigma varies much in all its characters, the 

 result, probably, of cultivation. The pollen-grains of 

 the short-styled form, according to Hildebrand,* are 

 7 divisions of the micrometer in length and 5 in 

 breadth; whereas those of the long-styled are only 

 4 in length and 3 in breadth. The grains, there- 

 fore, of the short-styled are to those of the long- 

 styled in length as 100 to 57. Hildebrand also re- 

 marked as I had done in the case of P. veris, that the 

 smaller grains from the long-styled are much more 

 transparent than the larger ones from the short-styled 

 form. We shall hereafter see that this cultivated 

 plant varies much in its trimorphic condition and is 

 often equal-styled. Some individuals may be said to 

 be sub-heterostyled ; thus in two white-flowered plants 

 the pistil projected above the stamens, but in one of 

 them it was longer and had a more elongated and 

 rougher stigma than in the other; and the pollen-grains 

 from the latter were to those from the plant with a more 

 elongated pistil only as 100 to 88 in diameter, instead 

 of as 100 to 57. The corolla of the long-styled and 

 short-styled forms differs in shape, in the same manner 

 as in P. veris. The long-styled plants tend to flower 



* After the appearance of my greatly about the size of the pol- 



paper this author published some len-grains in the two forms. I 



excellent observations on the pre- suppose that by mistake I meas- 



sent species ('Bot. Zeitnng,' Jan. 1, ured twice over pollen-grains 



1864), and he shows that I erred from the same form. 



