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Show 46 IPOMCEA PURPUREA. CHAP. U. d plants was roue h taller than any one oot f. Colchester-crosse the opposite side of the same p ' the intercrossed plants on ewhat taller. I should state and in the three other pots soro d plants in Pot IV., whmJ that two of the Colchester-crosse much diseased, and were, about two-thirds gro':n, becarode opponents rejected. Tlle . th · 1n tercrosse ' together With eu h almost fu1ly grown, wm·0 • • (J' nineteen plants, w en rmereoaasinuirned o, 'th the following result:-Wl TABLE XIII. Colchester-r.rossed No. of Pot. Plants. ---- - - [nches. I. 87 87 ~ 85i --- - II. 93§ 85~ 90~ - III. 84~ 92~ 85 - IV. 95~ v. 90~ 86 ~ 84 VI. 90~ Crowded plants in a 75 very large pot. 71 83 ~ 63 65 Total inches. 15~6·50 Jntercrossed Plant~ of the Tenth Generatwn. - Inches. 78 68 a 94~ --- - 60 87 ~ 45~ -- - 70A 81 ~ 86~ ----- - - - 65~ 85~ 63 62~ 1- 43~ ~9~ 30~ 86 53 48H - - 1249•75 ln sixteen out of these nineteen pau· s, the Colc, heTstheer- acvreorssaegde plant exceeded in height its interc~osse~ opp_on~t. and that of height of the Colcheste~-crossed IS 84 03 In;8 es'vVith respect the intercrossed 65.78 Inches; or as lOp to . CHAP. II. DESCENDANTS OF HERO. 47 to the fertility of the two lots, it was too tl'oublesome to collect and count the ca psulcs on all the plants ; so I selected two of the best pots, V. and VI., and in these the Colchester-crossed produced 269 mature and half-mature capsules, whilst an equal number of the intercrossed plants produced only 154 capsules; or as 100 to 57. By weight the capsules from the Colchestercrossed plants were to those from the intercrossed plants as 100 to 51; so that the former probably contained a somewhat larger average number of seeds. We learn from this important experiment that plants in some degree related, which had been intercrossed during the nine previous generations, when they were fertilised with pollen from a fresh stock, yielded seedlings as superior to the seedlings of the tenth intercrossed generation, as these latter were to the selffertilised plants of the corresponding generation. For if we look to the plants of the ninth generation in Table X. (and these offer in most respects the fairest standard of comparison) we find that the intercrossed plants were in height to the self-fertilised as 100 to 79, and in fertility as 100 to 26 ; whilst the Colchestercrossed plants are in height to the intercrossed as 100 to 78, and in fertility as 100 to 51. The Descendants of the self-fertilised Plant, named Ifero, which appeared in the Sixth self-fertilised Generation.-In the five generations before the sixth, the crossed plant of each pair was taller than its self-fertilised opponent; but in the sixth generation (Table VII., Pot II.) the Hero appeared, which after a long and dubious struggle conquered its crossed opponent, though by only half an inch. I was so much surprised at this fact, that I resolved to ascertain whether this plant would tl'ansmit its powers of growth to its seedlings. Several flowers on He1·o were therefore fertilised with their own pollen, and the seedlings thus raised were put into competition with self-fertilised and intercrossed plants of the corresponding generation. '.£he three lots of seedlings thus all belong to the seventh genera- |