Picture - Cosmic Polymath

EVIDENCES OF DESIGN IN REPRODUCTIVE ELEMENTS 155
PLATE LXI
Plate Ixi. illustrates globular, concentric, radiating, branched, segmented, curved, and spiral arrangements.
Fig. 1.— Portion of the epidermis of a salamander in slightly oblique horizontal section, magnified 550 diameters. Cells rounded
and polygonal, connected by delicate bridges of protoplasm and containing large nuclei (Wilson), a, Epidermal cells, three of which
are undergoing division. The earliest stage of division (spirem) is seen at 6/ a later stage (mitotic figure in the anaphase), showing
chromosomes at c; and the final stage (telophase), showing fission of cell-body at d. e, Branched dark pigment-cell which has crept up
from lower layers of skin. This figure illustrates circular, pentagonal, and branched arrangements.
Fig. 2.—Division of the blood-cells in the embryo chick according to Reinak. «, b, c, d, e, Successive stages of division ; /, cell
dividing by mitosis. This figure shows concentric and radiating arrangements.
Pig. 3.—Reticular nucleus («) of the rhizopod {Admosi)ha>riuiii) as figured by Brauer. The reticulation is a form of diff'erentiation—the
nucleus possessing a complex oi'ganisation.
Fig. 4.—Low animal form, Amceba proteiui, consisting of a single cell. Magnified 280 diameters (Sedgwick and Wilson).
n, Nucleus; wv, water vacuoles ; cv, contracting vacuole ; fv, food vacuole. The amoeba can reproduce itself and move voluntarily in
any direction. It reveals traces of difl'erentiation.
Fig. 5.—Diagram of a cell by Wilson. The basis of the cell consists of a thread-work (iniiome or reticulum) composed of minute
granules (microsomes), traversing a transparent ground-substance, a, Nucleus ; a, true nucleolus or plasmosome ; h, chromatin network
; c, linin-network ; d, net-knot or karyosome ; e, attraction-sphere containing two centrosomes ; /, /', vacuoles ; g, lifeless bodies
(nietaplasm) suspended in cytoplasmic reticulum ; h, plastids lying in cytoplasm.
This diagram shows that the cell is not, in any sense, a simple homogeneous body. On the contrary, it is differentiated to a
considerable extent, a circumstance too frequently overlooked. The cell is originally spherical in form, but becomes indented by
growth, crowding, and pressure.
Fig. 6.—A resting cell {Spurmatogonium) from testis of salamander, showing typical parts (Ravitz). w. Large nucleus bounded by
membrane and invested with cytoplasmic thread-work. Contains scattered masses of chromatin and linin-network. a, Attraction
sphere with centrosome (/j). The attraction-sphere is a centre of force, and can act either centripetally or centrifugally.
Fig. 7.—Living branched connective tissue-cell from salamander larva (Fleming). Affords beautiful example of branching
arrangement.
Fig. 8.—Living epidermal cell from larva of salamander in early mitosis (segmented spirem), surrounded by protoplasmic
bridges fFleming). Shows concentric, branching, and radiating arrangements.
FtG. 9.—Living dividing cell of salamander larva. The cell when dividing assumes a dumb-bell shape (Fleming).
Fig. 10.—Pigment-cell from epidermis of fish (Blennius), as given by Zimmerman, a, Central clear space of aster from which the
pigment-granules diverge; n, two nuclei. Shows radiating arrangement to advantage.
Fig. 11.—Pigment-cell of fish (Sarcjus) showing two nuclei (nn') with aster (»), and rod-shaped central mass (6), according to
Zimmerman. Affords good example of branching, radiating arrangements.
PLATE LXI I
Plate Ixii. illustrates globular, concentric, radiating, branched, dendritic, curved, and spindle arrangements
in the cell.
Pig. 1. —Leucocyte or wandering cell of the salamander as figured by Heidenhain. The cell contains a large nucleus (n) \yith
coarse network of chromatin, two nucleoli («'), and permanent aster (