This leads to the establishment of a percentage for
every single parent, and gives data for comparisons. Two or three
hundreds of seeds from a parent may easily be grown in one pan, and in
this way a sufficiently high degree of accuracy may be reached. Only
those parents that give [349] the highest percentage are chosen, and
among their progeny only the seedlings with trifoliolate primary leaves
are planted out. The whole procedure of the selection is by this means
confined to the glasshouse during the spring, and the beds need not be
large, nor do they require any special care during the summer.
By this method I brought my strain within two years up to an average of
nearly 90% of the seedlings with a divided primary leaf. Around this
average the real numbers fluctuated between the maximum of 99% and the
minimum of 70% or thereabouts. This condition was reached by the sixth
generation in the year 1894, and has since proved to be the limit, the
group of figures remaining practically the same during all the
succeeding generations.
Such selected plants are very rich in leaves with four, five and six
blades. Excluding the small leaves at the tops of the branches, and
those on the numerous weaker side-branches, these three groups include
the large majority of all the stronger leaves.
Pages:
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345