| Comparison with 1869 |
|
|
the male and female flowers may be produced on the same tree, we can see that
pollen must be regularly carried from flower to flower; and this will give a better chance of pollen being occasionally carried from tree to tree. That trees belonging to all Orders have their sexes more often separated than other plants, I find to be the case in this country; and at my request Dr. Hooker tabulated the trees of New Zealand, and Dr. Asa Gray those of the United States, and the result was as I anticipated. On the other hand, Dr. Hooker has recently
informed
me that he finds that
the rule does not hold in Australia; and
I have made these few remarks on the sexes of
trees simply to call attention to the subject. |
|
| Turning for a very
brief space to animals: on the land there are some hermaphrodites, as
land-mollusca and earth-worms; but these all pair. As yet I have not found a single case of a
terrestrial animal which fertilises
itself. We can understand
this
remarkable fact, which offers so strong a contrast with terrestrial plants, on
the view of an occasional cross being indispensable,
by considering the medium in which terrestrial animals live, and
the nature of the fertilising element;
for we know of
no means, analogous to the action of insects and of the wind in the case of
plants, by which an occasional cross could be effected with terrestrial animals without the concurrence of two individuals. Of aquatic animals, there are many self-fertilising hermaphrodites; but here currents in the
water offer an obvious means for an occasional cross. And, as
in the case of flowers, I have as yet failed, after consultation with one of the highest authorities, namely, Professor Huxley, to discover a single case of an
hermaphrodite animal with the organs of reproduction so perfectly enclosed within the body,
that access from without
and
|
the male and female flowers may be produced on the same tree,
we can see that | we can see that 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| has recently 1859 1860 1861 1866 1869 | has recently 1872 |
| informed 1859 1860 1861 1866 1869 | | informs 1872 |
| he finds that 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| in Australia; and 1859 1860 1861 1866 1869 |
| good in Australia: but if most of the Australian trees are dichogamous, the same result would follow as if they bore flowers with separated sexes. 1872 |
| the sexes of 1859 1860 1861 1866 1869 |
| OMIT 1872 |
|
|
Turning for a
very | very 1859 1860 1861 1866 1869 | very 1872 |
| on the land there are some hermaphrodites, as 1859 1860 1861 1866 1869 |
| various terrestrial species are hermaphrodites, such as the 1872 |
| case of a 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| fertilises 1859 1860 1861 1866 1869 | | can fertilise 1872 |
| We can understand 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| this 1859 1860 1861 1866 1869 | | This 1872 |
| on 1859 1860 1861 1866 1869 |
| is intelligible on 1872 |
| indispensable, 1859 1860 1861 1866 1869 | | indispensable; 1872 |
| by considering the medium in which terrestrial animals live, and 1859 1860 1861 1866 1869 |
| for owing to 1872 |
| element; 1859 1860 1861 1866 1869 | | element 1872 |
| for we know of 1859 1860 1861 1866 1869 |
| there are 1872 |
| in the case of 1859 1860 1861 1866 1869 |
| with 1872 |
| currents in the 1859 1860 1861 1866 1869 |
| the currents of 1872 |
| And, as 1859 1860 1861 1866 1869 | | As 1872 |
| case of an 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| within the body, 1859 1860 1861 1866 1869 |
| OMIT 1872 |
| without 1859 1860 1861 1866 1869 | | without, 1872 |
|
