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OriginOfSpecies - 475 Rows
Column Type #Values Column Stats
id int(11) 475 Column Stats
subject varchar(80) 14 Column Stats
title varchar(250) 139 Column Stats
ordinal int(11) 30 Column Stats
description text 474 Column Stats

475 rows, page 13 of 119 (4/p)
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Export to Excel select * from OriginOfSpecies order by ordinal limit 48, 4 (Page 13: Row)
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05 - Laws of Variation 05-04 - Correlation of Growth 10 I mean by this expression that the whole organisation is so tied together during its growth and development, that when slight variations in any one part occur, and are accumulated through natural selection, other parts become modified.

This is a very important subject, most imperfectly understood, and no doubt wholly different classes of facts may be here easily confounded together.

We shall presently see that simple inheritance often gives the false appearance of correlation.

One of the most obvious real cases is, that variations of structure arising in the young or larvae naturally tend to affect the structure of the mature animal.

larva
larva


The several parts of the body which are homologous, and which, at an early embryonic period, are identical in structure, and which are necessarily exposed to similar conditions, seem eminently liable to vary in a like manner: we see this in the right and left sides of the body varying in the same manner; in the front and hind legs, and even in the jaws and limbs, varying together, for the lower jaw is believed by some anatomists to be homologous with the limbs.
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These tendencies, I do not doubt, may be mastered more or less completely by natural selection; thus a family of stags once existed with an antler only on one side; and if this had been of any great use to the breed, it might probably have been rendered permanent by selection.
05 - Laws of Variation 05-08 - Parts Developed in an Unusual Manner are Highly Variable 10 A Part developed in any Species in an extraordinary degree or manner, in comparison with the same Part in allied Species, tends to be highly variable.
05 - Laws of Variation 05-05 - Compensation and Economy of Growth 10 The elder Geoffroy and Goethe propounded, at about the same time, their law of compensation or balancement of growth; or, as Goethe expressed it, "In order to spend on one side, nature is forced to economise on the other side."

I think this holds true to a certain extent with our domestic productions: if nourishment flows to one part or organ in excess, it rarely flows, at least in excess, to another part; thus it is difficult to get a cow to give much milk and to fatten readily.

cows
cows

milk
milk


The same varieties of the cabbage do not yield abundant and nutritious foliage and a copious supply of oil-bearing seeds.

cabbage
cabbage


When the seeds in our fruits become atrophied, the fruit itself gains largely in size and quality. In our poultry, a large tuft of feathers on the head is generally accompanied by a diminished comb, and a large beard by diminished wattles.

fruit
fruit

poultry
poultry
05 - Laws of Variation 05-07 - Multiple, Rudimentary, and Lowly-organised Structures are Variable 10 It seems to be a rule, as remarked by the younger Geoffroy, both with varieties and species, that when any part or organ is repeated many times in the same individual (as the vertebrae in snakes, and the stamens in polyandrous flowers) the number is variable; whereas the same part or organ, when it occurs in lesser numbers, is constant.

snake
snake


The same author as well as some botanists have further remarked that multiple parts are extremely liable to vary in structure. As "vegetable repetition," to use Prof. Owen's expression, is a sign of low organisation, the foregoing statements accord with the common opinion of naturalists, that beings which stand low in the scale of nature are more variable than those which are higher.
Richard Owen
Richard Owen