sexual elements of the distinct forms should act perfectly on one another. TRANSMISSION OF THE TWO FORMS BY HETEROSTYLED PLANTS. The transmission of the two forms by heterostyled plants, with respect to which many facts were given in the last chapter, may perhaps be found hereafter to throw some light on their manner of development. Hildebrand observed that seedlings from the long-styled form of Primula Sinensis when fertilised with pollen from the same form were mostly long-styled, and many analogous cases have since been observed by me. All the known cases are given in Tables 6.36 and 6.37. TABLE 6.36. Nature of the offspring from illegitimately fertilised dimorphic plants. Column 1: Species and form. Column 2: Number of long-styled offspring. Column 3: Number of short-styled offspring. Primula veris. Long-styled form, fertilised by own-form pollen during five successive generations : 156 : 6. Primula veris. Short-styled form, fertilised by own-form pollen : 5 : 9. Primula vulgaris. Long-styled form, fertilised by own-form pollen during two successive generations : 69 : 0. Primula auricula. Short-styled form, fertilised by own-form pollen, is said to produce during successive generations offspring in about the following proportions : 25 : 75. Primula Sinensis. Long-styled form, fertilised by own-form pollen during two successive generations : 52 : 0. Primula Sinensis. Long-styled form, fertilised by own-form pollen (Hildebrand) : 14 : 3. Primula Sinensis. Short-styled form, fertilised by own-form pollen: 1 : 24. Pulmonaria officinalis. Long-styled form, fertilised by own-form pollen : 11 : 0. Polygonum fagopyrum. Long-styled form, fertilised by own-form pollen : 45 : 4. Polygonum fagopyrum. Short-styled form, fertilised by own-form pollen : 13 : 20. TABLE 6.37. Nature of the offspring from illegitimately fertilised trimorphic plants. Column 1: Species and form. Column 2: Number of long-styled offspring. Column 3: Number of mid-styled offspring. Column 4: Number of short-styled offspring. Lythrum salicaria. Long-styled form, fertilised by own-form pollen : 56 : 0 : 0. Lythrum salicaria. Short-styled form, fertilised by own-form pollen : 1 : 0 : 8. Lythrum salicaria. Short-styled form, fertilised by pollen from mid-length stamens of long-styled form : 4 : 0 : 8. Lythrum salicaria. Mid-styled form, fertilised by own-form pollen : 1 : 3 : 0. Lythrum salicaria. Mid-styled form, fertilised by pollen from shortest stamens of long-styled form : 17 : 8 : 0. Lythrum salicaria. Mid-styled form, fertilised by pollen from longest stamens of short-styled form : 14 : 8 : 18. Oxalis rosea. Long-styled form, fertilised during several generations by own- form pollen, produced offspring in the ratio of : 100 : 0 : 0. Oxalis hedysaroides. Mid-styled form, fertilised by own-form pollen : 0 : 17 : 0.