102 BRASSICA OLERACEA. CHAP. IV 



Early in the spring the plants were gradually hardened, and 

 turned out of their pots into the open ground without being 

 disturbed. By the end of August the greater number had 

 formed fine heads, but several grew extremely crooked, from 

 having been drawn up to the light whilst in the greenhouse. 

 As it was scarcely possible to measure their heights, the finest 

 plant on each side of each pot was cut down close to the ground 

 and weighed. In the preceding table we have the result. 



The six finest crossed plants average 108*16 ounces, whilst 

 the six finest self-fertilised plants average only 23 7 ounces, or 

 as 100 to 22. This difference shows in the clearest manner the 

 enormous benefit which these plants derived from a cross with 

 another plant belonging to the same sub- variety, but to a fresh 

 stock, and grown during at least the three previous generations 

 under somewhat different conditions. 



The Offspring from a cut-leaved, curled, and variegated white 

 green Cabbage crossed with a cut-leaved, curled, and variegated 

 crimson-green Cabbage, compared with the self-fertilised Offspring 

 from the two Varieties. These trials were made, not for the 

 sake of comparing the growth of the crossed and self-fertilised 

 seedlings, but because I had seen it stated that these varieties 

 would not naturally intercross when growing uncovered and 

 near one another. This statement proved quite erroneous ; but 

 the white-green variety was in some degree sterile in my garden, 

 producing little pollen and few seeds. It was therefore no 

 wonder that seedlings raised from the self-fertilised flowers of this 

 variety were greatly exceeded in height by seedlings from a cross 

 between it and the more vigorous crimson-green variety ; and 

 nothing more need be said about this experiment. 



The seedlings from the reciprocal cross, that is, from the crim- 

 son-green variety fertilised with pollen from the white-green 

 variety, offer a somewhat more curious case. A few of these 

 crossed seedlings reverted to a pure green variety with their 

 leaves less cut and curled, so that they were altogether in a much 

 more natural state, and these plants grew more vigorously and 

 taller than any of the others. Now it is a strange fact that a 

 much larger number of the self-fertilised seedlings from the 

 crimson-green variety than of the crossed seedlings thus reverted ; 

 and as a consequence the self-fertilised seedlings grew taller by 

 2i inches on an average than the crossed seedlings, with which 

 they were put into competition. At first, however, the crossed 

 seedlings exceeded the self-fertilised by an average of a quarter 



