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Show 106 IBERIS UMBELLATA. CHAP. IV. TABLE XXXII. . Iberis umbe lla t a : 0 s~. gn'ti fui : s that the Plant d~ed. Plants from ~r.on-. No. of Pot. Plants from a Cruss taneously Sclf-fertJ- with a fre~;h Stock. lised Seeds. -------------- - ----ln- c-he-s.---- I. V. VI. 18~ 17 ·~ 17 ~ 20~ 20§ 15~ 17 - - ---------- - '------------,. -- ----------- - VII. Inc h e ~;. 17 ~ 1 6~ 1 3~ J ;) ~ -- 0 16 ~ 1.) ~ - ----1----~--~--- VIII. Total in inches. I . . f th thirty crossed p l an t s is (h eree The average hmght o e . If-fertilised plants on 17·34, and that of the twenty-nine se CHAP. IV. PAPAVEH VAGUl\ti. 107 having died) 15 ·51, or as 100 to 89. I am surprised that the difference did not provo somewhat greater, considering that in the last experiment it wa. as 100 to 86; but this latter ratio, as before explained, was probably too great. In should, however, be observed that in the last experiment (Table XXXI.), the crossed plants competed with plants of the third self-fertilised generation; whilst in the present case, plants derived from a cross with a frcRh stock competed with self-fertilised plants of the fir·st generation. The crossed plants in the present case, as in the last, were more fertile than the self-fertilised, both lots being left uncovered in the greenhouse. The thirty crossed plants produced 103 seed-bearing flower-heads, as well as some heads which yielded no seeds; whereas the twenty-nine self-fertilised plants produced only 81 seed-bearing heads; therefore thirty such plants would have produced <l3 ·7 heads. We thus got the ratio of 100 to 81, for the number of seed-bearing flower-heads produced by the crossed and self-fertilised plants . . Moreover, a number of seed-bearing heads from the crossed plants, compared with the same number from the self-fertilised, yielded seeds by weight, in the ratio of 100 to 92. Combining these two elements, viz., the number of seed-bearing heads and the weight of seeds in each head, the productiveness of the crossed to the self-fertilised plants was as 100 to 75. Tho crossed and self-fertilised seeds, which remained after the above pair• had been planted, (some in a state of germination and some not so), were sown early in the year out of doors in two rows. Many of the self-fel"tilised seedlings suffered greatly, and a much larger number of them perished than of the crossed. In the autumn the surviving selHertilised plants were plainly less well-grown than the crossed plants. VII. PAPAVERAOElE.-PAPAVER VAGUM. A sub-species of P. dubium, from the south of France. The poppy does not secrete nectar, but the flowers are highly conspicuous and are visited by many pollen-collecting bees, fiies and beetles. The anthers shed their pollen very eal'!y, and in the case of P. rhreas, it falls on the circumference of the radiating stigmas, sq that this species must often be self-fertilised; but with 1'. dubium the same result does not follow (according to H. Miiller, 'Die Befruchtung,' p. 128), owing to |