Picture - Cosmic Polymath

EVIDENCES OF DESIGN IN REPRODUCTIVE ELEMENTS 153
muscle-cell lies the riddle of the heart-beat, or of muscular contraction ; in the gland-cell are the causes of
secretion ; in the epithelial cell, in the white blood-cell, hes the problem of the absorption of food ; and the
secrets of the mind are slumbering in the ganglion-cell."
I will conclude this part of the work with one or two short extracts from an instructive volume — " The Cell
in Development and Inheritance " — published by Professor Edmond B. Wilson of Columbia University in 1896.
The volume referred to is amply illustrated, and I have to acknowledge my indebtedness to this distinguished
author for several figures in Plates lix., Ix., Ixi., and Ixii. His allusions to the relations subsisting between the
cell and hereditary descent are especially interesting. He observes, " The cell-theory first came into contact with
the evolution-theory through researches on the early history of the germ cells and the fertihsation of the ovum.
Begun in 1873-74 by Auerbach, Fol, and Biitschh, and eagerly followed up by Oscar Hertwig, van Beneden,
Strasburger, and a host of later workers, these investigations raised wholly new questions regarding the mechanism
of development and the role of the cell in hereditary transmission. The identification of the cell-nudeus as the
vehicle of inheritance, made independently and almost simultaneously in 1884-85 by Oscar Hertwig, Strasburger,
Kolliker, and Weismann, must be recognised as the first definite advance towards the internal problems of
inheritance through the cell-theory ; and the discussions to which it gave rise, in which Weismann has taken
the foremost place, must be reckoned as the most interesting and significant of the post-Darwinian period. . . .
By the extreme ' evolutionists ' or ' preeformationists ' the egg was believed to contain an embryo fully formed
in miniature, as the bud contains the flower or the chrysalis the butterfly. Development was to them merely
the unfolding of that which already existed ; inheritance, the handing down from parent to child of an infini-
tesimal reproduction of its own body. . . Caspar
Friedrich Wolff (1759) by precise actual observation showed
that the egg does not at first contain any formed embryo whatever ; that the structure is wholly different from
that of the adult ; that development is not a mere process of unfolding, but a progressive process, involving the
continual formation, one after another, of new parts, previously non-existent as such. This is somewhat as
Harvey, following Aristotle, had conceived it—a process of epigenesis as opposed to evolution. Later researches
established this conclusion as the very foundation of embryological science. . . It was reserved for Schwann (1839)
and his immediate followers to recognise the fact, conclusively demonstrated by all later researches, that the egg
is a cell having the same essential structure as other cells of the body. And thus the wonderful truth became
manifest that a single cell may contain within its microscopic compass the sum-total of the heritage of the species.
This conclusion, first reached in the case of the female sex, was soon afterwards extended to the male as well. . . .
Two years after the appearance of Schwann's epoch-making work Kolliker demonstrated (1841) that the spermatozoa
arise directly from cells in the testis, and hence cannot be regarded as parasites, but are, Uke the ovum,
derived from the parent-body. Not until 1865, however, was the final proof attained by Schweigger-Seidel and
La Valette St. George that the spermatozoon contains not only a nucleus, as Kolliker beheved, but also cytoplasm.
It was thus shown to be, like the egg, a single cell, peculiarly modified in structure, it is true, and of extraordinary
minuteness, yet on the whole morphologically equivalent to other cells. A final step was taken ten years later
(1875), when Oscar Hertwig estabhshed the all-important fact that fertihsation of the egg is accomphshed by its
union with one spermatozoon, and one only. In sexual reproduction, therefore, each sex contributes a single cell
of its own body to the formation of the offspring, a fact which shows that the sexes play, on the whole, equal
though not identical parts in hereditary transmission. The ultimate problems of sex, fertilisation, inheritance,
and development were thus shown to be cell-problems."
It only remains for me to direct attention to the figures of Plates hx., Ix., Ixi., and Ixii., where the globular,
concentric, radiating, branched, segmented, curved, and spiral arrangements to which I have so frequently referred
are delineated. These arrangements are predetermined, and while they can be traced both in the inorganic and
organic kingdoms they are especially observable in the cells of plants and animals, particularly in the repro-
ductive or sexual cells. They are fundamental in character, and proclaim their importance by manifesting
themselves at the very beginnings of plant and animal Kfe. The early appearance of these arrangements is a
starthng and unexpected fact, and one which has much significance, as it is calculated to unify and refer to a
common standard the ultimate structure of crystals, plants, and animals respectively, and to indicate the
presence of law, order, and design in the two great divisions of nature.
Plates Ixi., Ixii., Ixiii., and Ixiv. show that the globular, concentric, radiating, branched, segmented,
curved, and spiral arrangements which obtain in crystals, and in plants and animals, make their appearance at
the very threshold of Ufe, in cells and in the male and female reproductive elements. This points to general
laws in the inorganic and organic kingdoms, and to typical forms which assert themselves in dead and living
matter respectively,
VOL. I,
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