Q. E. D., or New Light on the Doctrine of Creation

of the various kinds of cells of which the v

arose by a sort of crystallization from a mother liquor; and as to structure, they looked upon the cell-wall as the really important part, the fluid contents being quite subordinate. Hugo von Mohl (1846) applied to the fluid contents of the cell the term "protoplasm," and Max Schultze (1861) showed that this protoplasm is really identical in all organisms, plants and animals, also that the cel

tood. Not until the last quarter of the nineteenth century was it settled that the nucleus of the cell is also a supremely im

ain structures, and thereafter are never diverted from this duty so as to do a different work or produce a different kind of structure. In the young embryo certain structures arise at certain predestined times in particular places, and only there and out of these cells alone. As to why it should be so, we cannot tell, save as the result of deliberate design and as an expression of the order-loving min

hat is, one cell specializes, let us say, in secretion, another in contractility, another in receiving and carrying stimuli, etc. In this way we will have the gland-cell, the muscle-cell, and the nerve-cell, each cell destined to produce one of these organs developing others

never grow or develop into any distinctly different type of cell with other and different functions. It is true that through pathologic degeneration the form and even t

aring on the philosophy of life in general that it may be allowable to establ

highest authorities on embryology,

e transformation of a cell of one kind of tissue into a cell of another kind of tissue; and further we encounter no instances of

foremost pathologists, as to the strict and r

the other, there is no new development or metaplasia of the most highly specialized tissues from less specialized tissues; a simple epithelium cannot in the vertebrate give rise to more complex glandular tissue, or to

aracters in a very remarkable degree under normal conditions. Under various abnormal conditions, however, these cells may become modified as to functions, so that cells or tissues of one type may assume more or less completely the characters of another type. "But," as

issue, epithelium, muscle, nerve, these do not again merge through metaplasia. There is no evidence that

y analogous to the variation which goes on among species of animals and plants. But, as we shall see later, there is a well marked limit to th

use of grafting a good kind of fruit onto a stock of poorer quality? The very permanency of the g