is remarkable in the case of Brassica, Tropaeolum,
Nemophila, and of the first generation of Ipomoea,
that the seedlings raised from them were inferior in
height and in other respects to the seedlings raised
from the crossed seeds. This fact shows how superior
in constitutional vigour the crossed seedlings must
have been, for it cannot be doubted that heavy and
fine seeds tend to yield the finest plants. Mr.
Galton has shown that this holds good with Lathyrus
odoratus; as has Mr. A.J. Wilson with the Swedish
turnip, Brassica campestris ruta baga. Mr. Wilson
separated the largest and smallest seeds of this latter
plant, the ratio between the weights of the two lots
being as 100 to 59, and he found that the seedlings
“from the larger seeds took the lead and maintained
their superiority to the last, both in height and
thickness of stem.” (9/17. ‘Gardeners’
Chronicle’ 1867 page 107. Loiseleur-Deslongchamp
’Les Cereales’ 1842 pages 208-219, was
led by his observations to the extraordinary conclusion
that the smaller grains of cereals produce as fine
plants as the large. This conclusion is, however,
contradicted by Major Hallet’s great success
in improving wheat by the selection of the finest
grains. It is possible, however, that man, by
long-continued selection, may have given to the grains
of the cereals a greater amount of starch or other
matter, than the seedlings can utilise for their growth.
There can be little doubt, as Humboldt long ago remarked,
that the grains of cereals have been rendered attractive
to birds in a degree which is highly injurious to
the species.) Nor can this difference in the growth
of the seedling turnips be attributed to the heavier
seeds having been of crossed, and the lighter of self-fertilised
origin, for it is known that plants belonging to this
genus are habitually intercrossed by insects.
With respect to the relative period of germination
of crossed and self-fertilised seeds, a record was
kept in only twenty-one cases; and the results are
very perplexing. Neglecting one case in which
the two lots germinated simultaneously, in ten cases
or exactly one-half many of the self-fertilised seeds
germinated before the crossed, and in the other half
many of the crossed before the self-fertilised.
In four out of these twenty cases, seeds derived from
a cross with a fresh stock were compared with self-fertilised
seeds from one of the later self-fertilised generations;
and here again in half the cases the crossed seeds,
and in the other half the self-fertilised seeds, germinated
first. Yet the seedlings of Mimulus raised from
such self-fertilised seeds were inferior in all respects
to the crossed seedlings, and in the case of Eschscholtzia
they were inferior in fertility. Unfortunately
the relative weight of the two lots of seeds was ascertained
in only a few instances in which their germination
was observed; but with Ipomoea and I believe with
some of the other species, the relative lightness
of the self-fertilised seeds apparently determined