Comparison with 1859 |
|
Text in this page (from paragraph 710, sentence 1200, word 54 to paragraph 800, sentence 500, word 62) is not present in 1859 |
When a young naturalist commences the study of a group of organisms quite unknown to him, he is at first much perplexed to
determine
what differences to consider as specific, and what as
varieties; varieties; 1859 1860 1861 | varietal; 1866 1869 1872 |
for he knows nothing of the amount and kind of variation to which the group is subject; and this shows, at least, how very generally there is some variation. But if he confine his attention to one class within one country, he will soon make up his mind how to rank most of the doubtful forms. His general tendency will be to make many species, for he will become impressed, just like the pigeon or
poultry-fancier poultry-fancier 1859 | poultry fancier 1860 1861 1866 1869 1872 |
before alluded to, with the amount of difference in the forms which he is continually studying; and he has little general knowledge of analogical variation in other groups and in other countries, by which to correct his first impressions. As he extends the range of his observations, he will meet with more cases of difficulty; for he will encounter a greater number of closely-allied forms. But if his observations be widely extended, he will in the end generally be enabled
to make up his own mind
which to call varieties and which species;
but he will succeed in this at the expense of admitting much variation,—
|
Quercus robur. Finally, De Candolle admits that out of the 300 species, which will be enumerated in his Prodromus as belonging to the oak family, at least two-thirds are provisional species, that is, are not known strictly to fulfil the definition above given of a true species.
For it
should be added that De Candolle no longer believes that species are immutable creations, but concludes that the derivative theory
of
the
succession of forms is the succession of forms is the 1866 1869 |
OMIT 1872 |
most natural one, "and the most accordant with the known facts in palæontology, geographical botany and zoology, of anatomical structure and
classification;" classification;" 1866 1869 | classification." 1872 |
but,
he
adds, adds, 1866 1869 | adds, 1872 |
direct direct 1866 1869 | direct 1872 |
proof proof 1866 1869 | proof 1872 |
is
still still 1866 1869 | still 1872 |
wanting. wanting. 1866 1869 | wanting. 1872 |
↑5 blocks not present in 1866 1869 1872; present in 1859 1860 1861 | Close investigation, in most cases, will bring naturalists to an agreement how to rank doubtful forms.
Yet it must be confessed,
that it is in the best-known countries that we find the greatest number of forms of doubtful value.
I have been struck with the fact, that if any animal or plant in a state of nature be highly useful to man, or from any cause closely attract his attention, varieties of it will almost universally be found recorded.
These varieties, moreover, will be often ranked by some authors as species.
Look at the common oak, how closely it has been studied; yet a German author makes more than a dozen species out of forms, which are very generally
considered as varieties; and in this country the highest botanical authorities and practical men can be quoted to show that the sessile and pedunculated oaks are either good and distinct species or mere varieties.
|
|
|
When a young naturalist commences the study of a group of organisms quite unknown to him, he is at first much perplexed
to to 1859 1860 1861 1866 1869 | in 1872 |
determine determine 1859 1860 1861 1866 1869 | determining 1872 |
what differences to consider as specific, and what as
varietal; varietal; 1866 1869 1872 | varieties; 1859 1860 1861 |
for he knows nothing of the amount and kind of variation to which the group is subject; and this shows, at least, how very generally there is some variation. But if he confine his attention to one class within one country, he will soon make up his mind how to rank most of the doubtful forms. His general tendency will be to make many species, for he will become impressed, just like the pigeon or
poultry fancier poultry fancier 1860 1861 1866 1869 1872 | poultry-fancier 1859 |
before alluded to, with the amount of difference in the forms which he is continually studying; and he has little general knowledge of analogical variation in other groups and in other countries, by which to correct his first impressions. As he extends the range of his observations, he will meet with more cases of difficulty; for he will encounter a greater number of closely-allied forms. But if his observations be widely extended, he will in the end generally be
enabled enabled 1859 1860 1861 1866 1869 | able 1872 |
to make up his own
mind mind 1859 1860 1861 1866 1869 | mind; 1872 |
which to call varieties and which species; which to call varieties and which species; 1859 1860 1861 1866 1869 |
OMIT 1872 |
but he will succeed in this at the expense of admitting much variation,—
|