Cuap. IV. DELPHINIUM CONSOLIDA. 129 



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; 

 bo that they were in fact of equal height. According to Professor 

 H. Hoffmann,* this plant is proterandrous ; 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.! 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 J ; 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 18G3 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 cap- 

 sules, 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 



* ' Zur Speciesfrage,' 1875, J Their structure is described 



p. 11. by E Mullor, ' Befruchtung,' &c., 



t Decaisne, ' Comptee-Eendus,' p. 1/2. 

 July, 1863, p. 5. 



