82 MR. €. DARWIN ON THE DIMORPHIC CONDITION 
vations in detail, though I am far from supposing that all cases of 
dimorphism are alike. The first idea which naturally occurred 
was, that the species were tending towards a dioicous condition ; 
that the long-styled plants, with their rougher stigmas, were more 
feminine in nature, and would produce more seed; that the short- 
styled plants, with their long stamens and larger pollen-grains, 
were more masculine in nature. Accordingly, in 1860, I marked 
some Cowslips of both forms growing in my garden, and others 
growing in an open field, and others in a shady wood, and gathered 
and weighed the seed. In each of these little lots the short-styled 
plants yielded, contrary to my expectation, most seed. Taking 
the lots together, the following is the result :— 
No. of 
| 
Weight of 
| No. of Vinbels Capsules in 
apsule seed 1 
Plants. produced. produced. grains. 
Short-styled Cowslips | 9 | 33 199 8&3 | 
Long-styled Cowslips 13 ol 261 91 | 
If we reduce these elements for comparison to similar terms, we 
have— 
| Weight | Pr | x. | 
| No. of eight | No.of |Weight) no, of Weight | 
| Plants. of send in | Umbels, i seed. | Capsules. fees | 
| Short-styled Cowslips | 10 | 92 100 | 9251 | 100 | 4l | 
| Long-styled Cowslips | 10 70 100 | 178 100 34 
So that, by all the standards of comparison, the short-styled are 
the most fertile; if we take the number of umbels (which is the 
fairest standard, for large and small plants are thus equalized), the 
short-styled plants produce more seed than the long-styled, in the 
proportion of four to three. 
In 1861 I tried the result in a fuller and fairer manner. I 
transplanted in the previous autumn a number of wild plants 
into a large bed in my garden, treating them all alike; the result 
was— 
| No. of No. of | Weight of | 
| Plants. | Umbels, | Seedin | 
| | grains | 
| | 
| — 
| — | | | 
, Short-styled Cowslips ... 47 | 173 745 
| Long-styled Cowslips ..... 58 ^ 208 | 692 
