We will now turn to the fertility of the 53 illegitimate long-styled
grandchildren, descended from the long-styled plant which was first fertilised
with its own pollen. The pollen in two of these plants included a multitude of
small and shrivelled grains. Nevertheless they were not very sterile; for 25
flowers, fertilised with their own pollen, produced 15 capsules, containing an
average of 16.3 seeds. As already stated, the probable average with legitimate
plants for a union of this nature is rather above 20 seeds. These plants were
remarkably healthy and vigorous, as long as they were kept under highly
favourable conditions in pots in the greenhouse; and such treatment greatly
increases the fertility of the cowslip. When these same plants were planted
during the next year (which, however, was an unfavourable one), out of doors in
good soil, 20 self-fertilised flowers produced only 5 capsules, containing
extremely few and wretched seeds.
Four long-styled great-grandchildren were raised from the self-fertilised
grandchildren, and were kept under the same highly favourable conditions in the
greenhouse; 10 of their flowers were fertilised with own-form pollen and yielded
the large proportion of 6 capsules, containing on an average 18.7 seeds. From
these seeds 20 long-styled great-great-grandchildren were raised, which were
likewise kept in the greenhouse.
Pages:
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318