742 Hens low. — The Origin of Monocotyledons from Dicotyledons , 
prove that acquired characters can be reproduced under diametrically 
opposite conditions of life. 
I have shown this to be the case with Ononis spinosa , &C . 1 If seeds be 
sown in a constantly wet soil and atmosphere, the spines are at first present, 
but reduced, in the seedlings. They grow into leafy branches in the second 
year. Similarly, if there be a warm, moist spring, the spines of the Barberry 
will grow out into large leaves. So, too, the Beet, naturally a perennial, 
under cultivation has become a biennial, this character being now hereditary ; 
but it has not prevented its ‘bolting’ and so passing into an annual. Lettuces, 
on the other hand, are naturally annuals, but when bolting return to this 
condition. 
But, in nature, innumerable instances exist which prove incontestably 
that acquired characters of plants can be maintained quite irrespective of 
the environment. This is seen in strong xerophytes with massy fleshy stems, 
such as of the Aloe and Agave type, as well as the Cactaceous, and in aqua¬ 
tics ; of which Ranunculus heterophyllus , described above, is a familiar 
example. Of course, this also applies to all terrestrial Monocotyledons. 
According to Weismann, acquired characters, derived by the soma from 
changes in the conditions of life, can only be hereditary, provided they 
influence the germ cells, which are supposed to exist contemporaneously 
with the direct actions of the environment. Plants, however, are unlike 
animals, in passing through a more or less extended period of vegetation 
from germination, during which those activities are at work upon the plant’s 
soma , i. e. before any trace of reproductive cells exist. It is not until the 
vegetative activities decline that certain vegetative cells pass over into or 
become reproductive cells. The continuity of protoplasm extending from 
one daughter nucleus to the other through the ‘ equatorial ’ cell-plate, may 
be the means of communicating the effects of external irritations, &c., to the 
very cells which become reproductive germ cells and sperm cells. 
It may be suggested that the movements of the chromosomes to the 
‘ north ’ and ‘ south ’ poles from the ‘ equator ’ are the means required for 
making these protoplasmic strands of continuity, whereby the communica¬ 
tions are kept up between the surface and the interior. 
Dr. Hugo de Vries’ experiments on Mutations clearly prove that marked 
differences in seedlings (greater than the ordinary ‘ individual differences ’) 
may be permanent from their origin, at least under circumstances in which 
they appeared ; for he does not seem to have tested them in markedly 
different soils. I notice Professor J. S. Henslow found, in 1827, the same 
thing to occur with Primulas; varieties came up in his sowings, of which 
he observed that some were permanent, others reverted, &c. 2 
1 Heredity of Acquired Characters in Plants (Murray). See also Origin of Plant Structures, 
1895, p. 54. 
2 Loudon’s Magazine of Natural History, iii. 406 and ix. 153. 
