We have already considered the great individual variability of the sexual appetite.
The variability of the wind in the arctic seas is a remarkable fact, and very often only a few minutes intervene between a calm and a frightful tempest.
In these seedlings there could hardly be a doubt that the pulvinus was becoming rudimentary and tending to disappear; and this accounts for its great variability in structure and function.
There is, however, some degree of variability in this respect, apparently dependent on the season and on the degree to which they have been illuminated during [page 122] the day.
But there is some variability with respect to which leaflets rise or fall.
Account for the variability of children in the same family.
Variability is, he stated, governed by unknown laws which are infinitely complex.
Nevertheless, he says, there is no lack of individual variability among the former hence their conservatism as regards colour cannot be attributed to their having but little tendency to vary.
Definite and Indefinite Variability Towards the end of his life Darwin recognised that variability is of two kinds--definite and indefinite.
Why various characters should have been transmitted sometimes in one way and sometimes in another is not in most cases known; but the period of variability seems often to have been the determining cause.
Canestrini[37] has collected of its variability in man.
How then are we to account for this general and remarkable coincidence between the period of variability and that of sexual selection,-- principles which are quite independent of each other?
We see variability in every tongue, and new words are continually cropping up; but as there is a limit to the powers of the memory, single words, like whole languages, gradually become extinct.
On the greater variability of the males of domesticated animals, see my 'Variation of Animals and Plants under Domestication,' vol.
Any slight sexual difference, however, would be difficult to detect, on account of the great variability of these organs.
Judging from all that we know of man and the lower animals, there has always been sufficient variability in the intellectual and moral faculties, for their steady advancement through natural selection.
Not only does variability appear to be induced in man and the lower animals by the same general causes, but in both the same characters are affected in a closely analogous manner.
The color-plate shows this variety very well--possibly too well, since one of its defects is variability in color, the variant usually being very light colored and not as attractive as the type.
The variability of leaves is usually within limits easily set and occurs most often in young plants, in extremes of soil and climate, and on very succulent growths or water-sprouts.
Plinth to illustrate the difference between variability (fluctuation) and variation (mutation) 64 6.
Thus, for example, in stature the index of variability (standard deviation) of certain classes of men is approximately 2.
This is called the index of variabilityor "standard deviation.
Plinth to illustrate the difference between variability (fluctuation) and variation (mutation).
That is, we must know the amount of variability as well as the extent of the greatest divergence from the average.
If we measured a large number of pairs of fathers and sons with respect to stature we should find each generation with a variabilitysuch as that illustrated in Fig.
This is done by reducing the index of variability to per cents of the group average, giving what is called the coefficient of variability.
Similarly the index of variability of the weight of a group of university students has been found to be about 16.
TABLE I Coefficients ofVariability of Certain Human Traits Adult Stature 3.
First of all a clear understanding of the basic ideas of variability and heredity must be had as a primary condition of an appreciation of their significance for the subject before us.
There seems to be no more design in the variability of organic beings, and in the action of natural selection, than in the course which the wind blows.
It makes me much wish (but I know that you have not time) that you could write more in detail, and give, for instance, the facts on the variability of the American wild fruits.
But the variability of any performance cannot be eliminated except by long practice, and not altogether even then.
It is curious to find the elementary fact of variability of reaction present in such a simple performance.
Distal ends of different radial tubes, exhibiting the great variability of this species.
Distal ends of various radial tubes of a single specimen, exhibiting the extraordinary variability of this species.
The relative lack of variability in the crania of ater may result from uniform environmental conditions, which have served to select for uniform characters in the populations.
The probable cessation of gene flow in the past between these two subspecies, allowing ater to be isolated for a time, may also, in part, account for the relative lack of variability in the crania of ater.
Do not these facts tend to show that the changes in fowls' wings are due to fluctuating variability and selective influences rather than to a general law whereby the effects of disuse are cumulatively inherited?
The continual variability of all parts of the higher animals gives scope for innumerable changes, and Nature is not in a hurry.
The striking variability of the human jaw is strongly opposed to the idea of its being under the direct and dominant control of so uniform a cause as ancestral use and disuse.
This species makes a very close approach in the general form and relative sizes of all the valves, and in the variability of the number of the whorls, to P.
Professor Macgillivray, I may add, has come to a similar conclusion regarding the extremevariability of the valves of this species.
Macgillivray, concerning the variability of this form, and I believe there is only one true species.
It would appear as if the great variability of the valves was connected with the absence of calcareous matter.
The extreme variability of this species is remarkable.
And even then the variability of species remains unaccounted for, except as we attribute to nature a purpose to modify persistent forms under a law that is immutable even in its variability.
The crystalline system presents no variability in types, but a rigid adherence to specific forms of definitely determined value.
Through simulation, variability is accounted for, relations are scrutinized, functional dependencies are tested over a wide array of data critical to the performance of new systems, or over a wide array of the people involved with them.
Instead of the permanence of the printed text, they prefer the variability of continually changing programs, of scanning and sampling, and of surfing the Internet.
The ability to meet such changes by a built-in design variability is, however, not only a test of design, but also of its implicit economic equation.
Compared to the variability of the speech, it is more stable.
Changes in the pragmatic framework in which people constitute themselves as religious result in tension between the variability of the elements involved in work or new aspects of social life and the claims of the eternal.
Increased intensity, the variability of structures of interaction, the distributed nature of practical involvement, all require variable frames of reference for knowledge and understanding.
The meaning of history is expressed in the variability of the connections ascertained from one text to another.
In its incipient phases as notation and record, genealogy still relied on images to a great extent (the family tree), but also on the spoken, maintaining a variability similar to that of the oral.
In those days methods and formulae were rather haphazard, especially in view of the fact that the daily variability of dry rubber content of latices was not then recognised.
Regarding the first of these claims, it has been shown[31] that the rubber is not uniform in its behaviour on vulcanisation, and that its variability is similar to that of rubber prepared by other processes.
The remaining characteristic of emotional speech which we have to notice is that of variability of pitch.
I), has criticized some of the results of the physical anthropologists and attempted to show that the theory of the greater variability of man has no legs to stand on.
It must be confessed that the testimony of anthropologists on the difference in variability of men and women is to be accepted with great caution.
Campbell points out in detail[50] that the male sex is more liable than the female to gross lesions of the nervous system--a fact which he attributes to the greater variability of the male.
The superior activity and variability of the male among lower forms has been pointed out in great detail by Darwin and confirmed by others.
In this connection we have an explanation of the alleged greater variability of the male.
The structural variability of man is mainly toward motion; woman's variational tendency is not toward motion, but toward reproduction.
By this principle greater variability is secured, and among the larger number of variations there is always a chance of the appearance of one of superior fitness.
Our second question, Is there a sex difference in variability in mental traits which would call for a differentiation of vocation on the ground of sex?
He thought the human female to be more variable than the human male, and he opined that, "since woman is the inferior animal and variability is a sign of inferiority," the conclusion was justified!
The pertinence of the data cited, however, lies in the fact that if any sex difference in physical variability could be established, this would suggest (though it would not prove) the existence of a sex difference in mental variability also.
Yet Pearson's article remained practically the only literature of fact regarding the comparative anatomical variability of the sexes until the year 1914.
The statistical result shows no difference whatever in variability between the sexes.
The Comparative Variability of the Sexes at Birth," American Journal of Sociology, Oct.
The average variability or degree of divergence for all the twenty-four traits is taken as the standard and each trait compared with this standard.
Beyond the twenty-fifth trial the variability in these tests is much reduced, and particularly so in the measures here used, which are in all cases, after the preliminary trial, the medians of five successive trials.
But these two factors--decrease in variability and change in the character of the tests--seem to be far from sufficient to account for the results.
This means great individual variability and considerable consequent unreliability of the data.
A variability of one hundred thus indicates the average amount of disagreement.
The first discussion of the comparative variability of the sexes was broached about a century ago by an anatomist, Meckel.
This momentary variability need not be supposed to affect all the tests in the same way nor all individuals in the same direction.
Since inheritance is bi-parental, and since variation means some peculiarity in the inheritance, a greater variability in men, if true, would not mean that men had any credit for varying.
I have already alluded to the general belief in the greater degree of variability in men, which, if established, would on the psychical side involve an accentuated individualism and hence a greater possibility of genius.
Moreover the differences of variability are slight, less than those between members of the same race living in different conditions.
What I want to make clear is that this greater variability of man has not been established, and therefore cannot be accepted as a condition of male genius.
Of some significance, again, is the variability in the mental power of genius, leading to what may be called "a periodicity in production.
It is held that men have greater mental variabilityand more originality, while women have greater stability and more common sense.
Manouvrier, Karl Pearson, Frossetto, and especially Guiffrida-Ruggieri have brought forward evidence to prove the fallacy of this belief in the slighter variability and infantile character of woman.
This journal repeated, with accompanying examples, the exposition that we have just given of the variability of value, but without arriving, as we did, at the contradiction.
Now that is precisely what the gentlemen of the Academy deny: they are unwilling to admit that, if value is variable, it is for that very reason determinable; that variability is the sign and condition of determinability.
How account, in short, by our law of proportion, for the variability of the value of the calendar?
