This species bears white flowers and inhabits Southern Brazil. Hildebrand says that the stigma of the long-styled form is somewhat larger than that of the mid- styled, and this than that of the short-styled. The pistil of the latter is clothed with a few hairs, whilst it is very hairy in the other two forms. The diameter of the pollen-grains from both sets of the longest stamens equals 9 divisions of the micrometer,--that from the mid-length stamens of the long- styled form between 8 and 9, and of the short-styled 8,--and that from the shortest stamens of both sets 7. So that the extreme difference in diameter is as 9 to 7 or as 100 to 78. The experiments made by Hildebrand, which are not so numerous as in the last case, are given in Table 4.28 in the same manner as before. TABLE 4.28. Oxalis Regnelli (from Hildebrand). Column 1: Nature of the Union. Column 2: Number of Flowers fertilised. Column 3: Number of Capsules produced. Column 4: Average Number of Seeds per Capsule. Long-styled by pollen of longest stamens of short-styled. Legitimate union : 6 : 6 : 10.1. Long-styled by pollen of longest stamens of mid-styled. Legitimate union : 5 : 5 : 10.6. Long-styled by pollen of own mid-length stamens. Illegitimate union : 4 : 0 : 0. Long-styled by pollen of own shortest stamens. Illegitimate union : 1 : 0 : 0. Mid-styled by pollen of mid-length stamens of short-styled. Legitimate union : 9 : 9 : 10.4. Mid-styled by pollen of mid-length stamens of long-styled. Legitimate union : 10 : 10 : 10.1. Mid-styled by pollen of own longest stamens. Illegitimate union : 9 : 0 : 0. Mid-styled by pollen of own shortest stamens. Illegitimate union : 2 : 0 : 0. Mid-styled by pollen of longest stamens of short-styled. Illegitimate union : 1 : 0 : 0. Short-styled by pollen of shortest stamens of mid-styled. Legitimate union: 9 : 9 : 10.6. Short-styled by pollen of shortest stamens of long-styled. Legitimate union: 2 : 2 : 9.5. Short-styled by pollen of own mid-length stamens. Illegitimate union : 12 : 0 : 0. Short-styled by pollen of own longest stamens. Illegitimate union : 9 : 0 : 0. Short-styled by pollen of mid-length stamens of long-styled. Illegitimate union: 1 : 0 : 0. The results are nearly the same as in the last case, but more striking; for 41 flowers belonging to the three forms fertilised legitimately all yielded capsules, containing on an average 10.31 seeds; whilst 39 flowers fertilised illegitimately did not yield a single capsule or seed. Therefore the fertility of the six legitimate to that of the several illegitimate unions, as judged both by the proportion of flowers which yielded capsules and by the average number of contained seeds, is as 100 to 0. Oxalis speciosa.