CHAP. IV. CROSS WITH A FBESH STOCK. 105 



The average height of the seven crossed plants is here 19 12 

 inches, and that of the seven self-fertilised plants 16 '39, or as 

 100 to 86. But as the plants on the self-fertilised side grew 

 very unequally, this ratio cannot be fully trusted, and is probably 

 too high. In both pots a crossed plant flowered before any one 

 of the self-fertilised. These plants were left uncovered in the 

 greenhouse; but from being too much crowded they were not 

 very productive. The seeds from all seven plants of both lots 

 were counted ; the crossed produced 206, and the self-fertilised 

 154; or as 100 to 75. 



Cross by afresh Stock. From the doubts caused by the two 

 first trials, in which it was not known with certainty that the 

 plants had been crossed; and from the crossed plants in the 

 last experiment having been put into competition with plants 

 selMertilised for three generations, which moreover grew very 

 unequally, I resolved to repeat the trial on a larger scale, and 

 in a rather different manner. I obtained seeds of the same 

 crimson variety of J. umbellata from another nursery garden, 

 and raised plants from them. Some of these plants were allowed 

 to fertilise themselves spontaneously under a net; others were 

 crossed by pollen taken from plants raised from seed sent me by 

 Dr. Durando from Algiers, where the parent-plants had been cul- 

 tivated for some generations. These latter plants differed in hav- 

 ing pale pink instead of crimson flowers, but in no other respect. 

 That the cross had been effective (though the flowers on the crim- 

 son mother-plant had not been castrated) was well shown when the 

 thirty crossed seedlings flowered, for twenty -four of them produced 

 pale pink flowers, exactly like those of their father ; the six others 

 having crimson flowers exactly like those of their mother 

 and like those of all the self-fertilised seedlings. This case 

 offers a good instance of a result which not rarely follows 

 from crossing varieties having differently coloured flowers; 

 namely, that the colours do not blend, but resemble perfectly those 

 either of the father or mother plant. The seeds of both lots, 

 after germinating on sand, were planted on opposite sides of 

 eight pots. When fully grown, the plants were measured to 

 the summits of the flower-heads, as shown in the following 

 table : 



