SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 140 | Next

Darwin, Charles, 1809-1882

"Effects of Cross and Self Fertilisation in the Vegetable Kingdom"


TABLE 3/26. Gesneria pendulina.
Heights of Plants measured in inches.
Column 1: Number (Name) of Pot.
Column 2: Crossed Plants.
Column 3: Self-fertilised Plants.
Pot 1 : 42 2/8 : 39.
Pot 1 : 24 4/8 : 27 3/8.
Pot 2 : 33 : 30 6/8.
Pot 2 : 27 : 19 2/8.
Pot 3 : 33 4/8 : 31 7/8.
Pot 3 : 29 4/8 : 28 6/8.
Pot 4 : 30 6/8 : 29 6/8.
Pot 4 : 36 : 26 3/8.
Total : 256.50 : 233.13.
The average height of the eight crossed plants is 32.06 inches, and that
of the eight self-fertilised plants 29.14; or as 100 to 90.
4. LABIATAE.--Salvia coccinea. (3/12. The admirable mechanical
adaptations in this genus for favouring or ensuring cross-fertilisation,
have been fully described by Sprengel, Hildebrand, Delpino, H. Muller,
Ogle, and others, in their several works.)
This species, unlike most of the others in the same genus, yields a good
many seeds when insects are excluded. I gathered ninety-eight capsules
produced by flowers spontaneously self-fertilised under a net, and they
contained on an average 1.45 seeds, whilst flowers artificially
fertilised with their own pollen, in which case the stigma will have
received plenty of pollen, yielded on an average 3.3 seeds, or more than
twice as many. Twenty flowers were crossed with pollen from a distinct
plant, and twenty-six were self-fertilised. There was no great
difference in the proportional number of flowers which produced capsules
by these two processes, or in the number of the contained seeds, or in
the weight of an equal number of seeds.


Pages:
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152
The request /download_links.php was not found on this server.