Chap. VI. CANNA WARSCEWICZI. 231 



According to Delpino, bees eagerly visit the flowers in North 

 Italy, but I have never seen any insect visiting the flowers of the 

 present species in my hothouse, although many plants grew 

 there during several years. Nevertheless these plants produced 

 plenty of seed, as they likewise did when covered by a net ; they 

 are therefore fully capable of self-fertilisation, and have probably 

 been self-fertilised in this country for many generations. As 

 they are cultivated in pots, and are not exposed to competition 

 with surrounding plants, they have also been subjected for a 

 considerable time to somewhat uniform conditions. This, there- 

 fore, is a case exactly parallel with that of the common pea, in 

 which we have no right to expect much or any good from 

 intercrossing plants thus descended and thus treated; and 

 no good did follow, excepting that the cross-fertilised flowers 

 yielded rather more seeds than the self-fertilised. This species 

 was one of the earlier ones on which I experimented, and as I 

 had not then raised any self-fertilised plants for several successive 

 generations under uniform conditions, I did not know or even 

 suspect that such treatment would interfere with the advantages 

 to be gained from a cross. I was therefore much surprised at 

 the crossed plants not growing more vigorously than the self- 

 fertilised, and a large number of plants were raised, notwith- 

 standing that the present species is an extremely troublesome 

 one to experiment on. The seeds, even those which have been 

 long soaked in water, will not germinate well on bare sand ; and 

 those that were sown in pots (which plan I was forced to follow) 

 germinated at very unequal intervals of time; so that it was 

 difficult to get pairs of the same exact age, and many seedlings 

 had to be pulled up and thrown away. My experiments were 

 continued during three successive generations; and in each 

 generation the self-fertilised plants were again self-fertilised, 

 their early progenitors in this country having probably been self- 

 fertilised for many previous generations. In each generation, 

 also, the crossed plants were fertilised with pollen from another 

 crossed plant. 



Of the flowers which were crossed in the three generations, 

 taken together, a rather larger proportion yielded capsules thar: 

 did those which were self-fertilised. The seeds were counted in 

 forty-seven capsules from the crossed flowers, and they con- 

 tained on an average 9 ' 95 seeds ; whereas forty -eight capsules 

 from the self-fertilised flowers contained on an average 8*45 

 seeds ; or as 100 to 85. The seeds from the crossed flowers were 



