Table 4/43.  Adonis aestivalis.

Heights of plants measured in inches.

Column 1:  Number (Name) of Pot.

Column 2:  Crossed Plants.

Column 3:  Self-fertilised Plants.

Pot 1 :  14 :  13 4/8. 
Pot 1 :  13 4/8 :  13 4/8.

Pot 2 :  16 2/8 :  15 2/8. 
Pot 2 :  13 2/8 :  15.

Total :  57.00 :  57.25.

The average height of the four crossed plants is 14.25, and that of the four self-fertilised plants 14.31; or as 100 to 100.4; so that they were in fact of equal height.  According to Professor H. Hoffman, this plant is proterandrous (4/7.  ‘Zur Speciesfrage’ 1875 page 11.); nevertheless it yields plenty of seeds when protected from insects.

Delphinium consolida.

It has been said in the case of this plant, as of so many others, that the flowers are fertilised in the bud, and that distinct plants or varieties can never naturally intercross. (4/8.  Decaisne ‘Comptes-Rendus’ July 1863 page 5.) But this is an error, as we may infer, firstly from the flowers being proterandrous,—­the mature stamens bending up, one after the other, into the passage which leads to the nectary, and afterwards the mature pistils bending in the same direction; secondly, from the number of humble-bees which visit the flowers (4/9.  Their structure is described by H. Muller ‘Befruchtung’ etc., page 122.); and thirdly, from the greater fertility of the flowers when crossed with pollen from a distinct plant than when spontaneously self-fertilised.  In the year 1863 I enclosed a large branch in a net, and crossed five flowers with pollen from a distinct plant; these yielded capsules containing on an average 35.2 very fine seeds, with a maximum of forty-two in one capsule.  Thirty-two other flowers on the same branch produced twenty-eight spontaneously self-fertilised capsules, containing on an average 17.2 seeds, with a maximum in one of thirty-six seeds.  But six of these capsules were very poor, yielding only from one to five seeds; if these are excluded, the remaining twenty-two capsules give an average of 20.9 seeds, though many of these seeds were small.  The fairest ratio, therefore, for the number of seeds produced by a cross and by spontaneous self-fertilisation is as 100 to 59.  These seeds were not sown, as I had too many other experiments in progress.

In the summer of 1867, which was a very unfavourable one, I again crossed several flowers under a net with pollen from a distinct plant, and fertilised other flowers on the same plant with their own pollen.  The former yielded a much larger proportion of capsules than the latter; and many of the seeds in the self-fertilised capsules, though numerous, were so poor that an equal number of seeds from the crossed and self-fertilised capsules were in weight as 100 to 45.  The two lots were allowed to germinate on sand, and pairs were planted on the opposite sides of four pots.  When nearly two-thirds grown they were measured, as shown in Table 4/44.