Chap. I. SUMMAEY ON PKIMULA. 40 



styled form are, as usual, " larger, less transparent, and more 

 bluntly triangular than those from the long-styled plants." The 

 fertility of the two legitimate unions to that of the two ille- 

 gitimate unions is by the first standard as 100 to 74, and by 

 the second standard as 100 to 66. 



Pbimula involucbata. 



The pistil of the long-styled form is about thrice as long as 

 that of the short-styled ; the stigma of the former is globular 

 and closely beset with papillsB, whilst that of the short-styled 

 is smooth and depressed on the apex. The pollen-grains of the 

 two forms differ in size and transparency as before, but not in 

 shape. The fertility of the two legitimate to that of the two 

 illegitimate unions is by the first standard as 100 to 72 ; and by 

 the second standard as 100 to 47. 



Peimula fakinosa. 



According to Mr. Scott, the pistil of the long-styled form is 

 only about twice as long as that of the short-styled. The 

 stigmas of the two forms differ but little in shape. The pollen- 

 grains differ in the usual manner in size, but not in form. The 

 fertility of the two legitimate to that of the two illegitimate 

 unions is by the first standard as 100 to 71, and by the second 

 standard as 100 to 44. 



Smnmary on the foregoing heterosiyled species of Pri- 

 mula. — The fertility of the long and short-styled plants 

 of the above species of Primula, when the two forms 

 are fertilised legitimately, and illegitimately with 

 pollen of the same form taken &om a distinct plant, 

 has now been given. The results are seen in the fol- 

 lowing table ; the fertility being judged by two 

 standards, namely, by that of the proportional number 

 of flowers which yielded capsules, and by that of the 

 average number of seeds per capsule. But for full 

 accuracy many more observations, under varied condi- 

 tions, would be requisite. 



