Effects of Cross and Self Fertilisation in the Vegetable Kingdom eBook

This eBook from the Gutenberg Project consists of approximately 516 pages of information about Effects of Cross and Self Fertilisation in the Vegetable Kingdom.

Effects of Cross and Self Fertilisation in the Vegetable Kingdom eBook

This eBook from the Gutenberg Project consists of approximately 516 pages of information about Effects of Cross and Self Fertilisation in the Vegetable Kingdom.

Total :  17.5 :  8.0.

The six crossed plants here average 2.91, and the six self-fertilised 1.33 inches in height; so that the former were more than twice as high as the latter, or as 100 to 46.

In the spring of the succeeding year (1869) the three crossed plants in Pot 1 had all grown to nearly a foot in height, and they had smothered the three little self-fertilised plants so completely that two were dead; and the third, only an inch and a half in height, was dying.  It should be remembered that these plants had been bedded out in their pots, so that they were subjected to very severe competition.  This pot was now thrown away.

The six plants in Pot 2 were all alive.  One of the self-fertilised was an inch and a quarter taller than any one of the crossed plants; but the other two self-fertilised plants were in a very poor condition.  I therefore resolved to leave these plants to struggle together for some years.  By the autumn of the same year (1869) the self-fertilised plant which had been victorious was now beaten.  The measurements are shown in Table 5/59.

Table 5/59.  Pot 2.—­Sarothamnus scoparius.

Heights of plants measured in inches.

Column 1:  Crossed Plants.

Column 2:  Self-fertilised Plants.

       :  15 6/8 :  13 1/8.
       :  9 6/8 :  3.
       :  8 2/8 :  2 4/8.

The same plants were again measured in the autumn of the following year, 1870.

Table 5/60.  Pot 2.—­Sarothamnus scoparius.

Heights of plants measured in inches.

Column 1:  Crossed Plants.

Column 2:  Self-fertilised Plants.

       :  26 2/8 :  14 2/8.
       :  16 4/8 :  11 4/8.
       :  14 :  9 6/8.

Total :  56.75 :  35.50.

The three crossed plants now averaged 18.91, and the three self-fertilised 11.83 inches in height; or as 100 to 63.  The three crossed plants in Pot 1, as already shown, had beaten the three self-fertilised plants so completely, that any comparison between them was superfluous.

The winter of 1870-1871 was severe.  In the spring the three crossed plants in Pot 2 had not even the tips of their shoots in the least injured, whereas all three self-fertilised plants were killed half-way down to the ground; and this shows how much more tender they were.  In consequence not one of these latter plants bore a single flower during the ensuing summer of 1871, whilst all three crossed plants flowered.

Ononis minutissima.

This plant, of which seeds were sent me from North Italy, produces, besides the ordinary papilionaceous flowers, minute, imperfect, closed or cleistogene flowers, which can never be cross-fertilised, but are highly self-fertile.  Some of the perfect flowers were crossed with pollen from a distinct plant, and six capsules thus produced yielded on an average 3.66 seeds, with a maximum of five in one.  Twelve perfect

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Effects of Cross and Self Fertilisation in the Vegetable Kingdom from Project Gutenberg. Public domain.