TABLE 2/18. Ratio of productiveness of crossed and self-fertilised plants. Ipomoea purpurea. FIRST GENERATION OF CROSSED AND SELF-FERTILISED PLANTS GROWING IN COMPETITION WITH ONE ANOTHER. Sixty-five capsules produced from flowers on five crossed plants fertilised by pollen from a distinct plant, and fifty-five capsules produced from flowers on five self-fertilised plants fertilised by their own pollen, contained seeds in the proportion of : 100 to 93. Fifty-six spontaneously self-fertilised capsules on the above five crossed plants, and twenty-five spontaneously self-fertilised capsules on the above five self-fertilised plants, yielded seeds in the proportion of : 100 to 99. Combining the total number of capsules produced by these plants, and the average number of seeds in each, the above crossed and self-fertilised plants yielded seeds in the proportion of : 100 to 64. Other plants of this first generation grown under unfavourable conditions and spontaneously self-fertilised, yielded seeds in the proportion of : 100 to 45. THIRD GENERATION OF CROSSED AND SELF-FERTILISED PLANTS. Crossed capsules compared with self-fertilised capsules contained seeds in the ratio of : 100 to 94. An equal number of crossed and self-fertilised plants, both spontaneously self-fertilised, produced capsules in the ratio of : 100 to 38. And these capsules contained seeds in the ratio of : 100 to 94. Combining these data, the productiveness of the crossed to the self-fertilised plants, both spontaneously self-fertilised, was as : 100 to 35. FOURTH GENERATION OF CROSSED AND SELF-FERTILISED PLANTS. Capsules from flowers on the crossed plants fertilised by pollen from another plant, and capsules from flowers on the self-fertilised plants fertilised with their own pollen, contained seeds in the proportion of : 100 to 94. FIFTH GENERATION OF CROSSED AND SELF-FERTILISED PLANTS. The crossed plants produced spontaneously a vast number more pods (not actually counted) than the self-fertilised, and these contained seeds in the proportion of : 100 to 89. NINTH GENERATION OF CROSSED AND SELF-FERTILISED PLANTS. Fourteen crossed plants, spontaneously self-fertilised, and fourteen self-fertilised plants spontaneously self-fertilised, yielded capsules (the average number of seeds per capsule not having been ascertained) in the proportion of : 100 to 26. PLANTS DERIVED FROM A CROSSED WITH A FRESH STOCK COMPARED WITH INTERCROSSED PLANTS. The offspring of intercrossed plants of the ninth generation, crossed by a fresh stock, compared with plants of the same stock intercrossed during ten generations, both sets of plants left uncovered and naturally fertilised, produced capsules by weight as : 100 to 51.