The selection in this year was by no means easy. Nearly all the
individuals produced at least some quaternate leaves, and thereby showed
the variety to be quite pure. I counted the abnormal organs on a large
group of the best plants, and selected 20 excellent specimens from them,
with more than one-third of all their leaves changed in the desired
manner. Having brought my race up to this point, I [347] was able to
introduce a new and far more easy mark, afforded by the seedlings, for
my selections. This mark has since remained constant, and has brought
about a rapid continuance of the improvement, without necessitating such
large cultures.
This seedling in the various species of clover usually begins with a
first leaf above the cotyledons of a different structure from those that
follow. It has only one blade instead of three. But in my variety the
increase of the number of the leaflets may extend to these primary
organs, and make them binate or even ternate. Now it is obvious that an
individual, which begins with a divided primary leaf, will have a
greater tendency to produce a large number of supernumerary leaflets
than a plant which commences in the ordinary way. Or in other words, the
primary leaves afford a sure criterion for the selection, and this
selection may be made in the seed-pans.
Pages:
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343