United States or Saudi Arabia ? Vote for the TOP Country of the Week !
The farmer, the manufacturer, the soldier, clerk, and artisan do not all work in the same way; they undertake one or another of the economic tasks which they may be best fitted by circumstances to perform. Their differentiation and division of labor are identical with the diversity in structure and in function as well, exhibited by the cells of a living creature.
On the other hand, they differ among themselves in certain regards: in the degree of specialization and differentiation of divine functions, and in the stress that they lay on the various departments of human life.
To these modern preformationists are opposed the modern upholders of epigenesis or gradual differentiation, who attempt to elaborate a mechanical theory of development. And with the contrast between these two schools there is necessarily associated the discussion as to the inheritance or non-inheritance of acquired characters.
Similarly then, in the absence of that action of the medium by which was effected the differentiation of outer from inner in those microscopic portions of protoplasm constituting the earliest and simplest animals and plants, there could not have existed this cardinal trait of composition which all the higher animals and plants show us.
Then will all sorrow disappear. What can cause me sorrow? I am the One Existence of the universe. Then all jealousies will disappear; of whom to be jealous? Of myself? Then all bad feelings disappear. Against whom will I have this bad feeling? Against myself? There is none in the universe but me. ... Kill out this differentiation; kill out this superstition that there are many.
It is true alike that, during the period in which the Earth has been peopled, the human organism has grown more heterogeneous among the civilized divisions of the species; and that the species, as a whole, has been growing more heterogeneous in virtue of the multiplication of races and the differentiation of these races from each other.
The law which regulates the differentiation of species applies with especial significance when we consider the birth of human individuals; the law which ordains that out of countless millions of animalculae which once shed their remains on the floor of the deep sea, or that now swarm in any pond, there shall be no two alike, holds accurately for the myriads of men who are born and pass away.
But here it might be argued, on the other hand, that the spheroidal Echinoids, in reality, depart further from the general plan and from the embryonic form than the elongated Spatangoids do; and that the peculiar dental apparatus and the pedicellariae of the former are marks of at least as great differentiation as the petaloid ambulacra and semitae of the latter.
But the cells are still all alike, each one performs all functions equally well. But in volvox division of labor and differentiation of structure have taken place. Certain cells have become purely reproductive, while the rest gather nutriment for these, but are at the same time sensitive and locomotive, excretory and respiratory.
A step higher we find the cell cluster, and with it begins that differentiation which has continued to this day and which still continues. Simplicity has yielded to complexity and a new epoch of life been inaugurated. The outer cells of the cluster are more exposed to environmental forces than are the inner cells; they cohere more tenaciously and a rudimentary skin is formed.
Word Of The Day