80 MR. C. DARWIN ON THE DIMORPHIC CONDITION 
proof of the permanence of the two forms is seen in nursery gar- 
dens, where choice varieties of the Polyanthus are propagated by 
division; and I found whole beds of several varieties, each consisting 
exclusively of the one or the other form. The two forms exist in 
the wild state in about equal numbers: I collected from several 
different stations, taking every plant which grew on each spot, 
522 umbels ; 241 were long-styled, and 281 short-styled. No dif- 
ference in tint or size could be perceived in the two great masses 
of flowers. 
J examined many cultivated Cowslips (P. veris) or Polyanthuses, 
and Oxlips ; and the two forms always presented the same differ- 
ences, including the same relative difference in the size of the 
pollen-grains. 
Primula Auricula presents the two forms; but amongst the 
improved faney kinds the long-styled are rare, as these are less 
valued by florists, and seldomer distributed. There is a much 
greater relative inequality in the length of the pistils and stamens 
than in the Cowslip, the pistil in the long-styled form being nearly 
four times as long as in the short-styled, in which it is barely 
longer than the ovarium ; the stigma is nearly of the same shape 
in both forms, but it is rougher in the long-styled, though the 
difference is not so great as in the two forms of the Cowslip. In 
the long-styled plants the stamens are very short, rising but little 
above the ovarium. The pollen-grains of these short stamens from 
the long-styled plants, when distended with water, were barely 
soso Of an inch in diameter, whereas those from the long stamens 
of the short-styled plants were barely «ss, showing a relative 
difference of five to seven. The smaller grains of the long-styled 
plants were much more transparent, and before distention with 
water more triangular in outline than those of the other form. 
In one anomalous specimen with a long pistil, the stamens almost 
surrounded the stigma, so that they occupied the position proper 
to the stamens of the short-styled form; but the small size of the 
pollen-grains showed that these stamens had been abnormally de- 
veloped in length, and that the anthers ought to have stood at the 
base of the corolla. 
In the two forms of Primula Sinensis, the pistil is about twice as 
long in the one as in the other. The stigma of the long-styled 
varies much in shape, but is considerably more elongated and 
rougher than that of the short-styled, the latter being nearly 
smooth and spherical, but depressed on the summit. The shape 
of the throat of the corolla in the two forms differs as in the Cow- 
