Plant and animal
On this page the embryonic development of a flowering plant
and a simple animal (a sea urchin) are described
and compared from a Goethean point of view, also known as
phenomenology. The fundamental
difference between the shape and essence of a plant
and an animal will be explained.
development of the embryo of the plant
When plants flower, pollen will be carried from the stamens to the
stigma of the pistil by wind, insects or other animals. The
pollen makes a tube through the style of the pistil to the egg cell in
the ovary. Fertilization takes place and then follows the first
division (see Fig. 1, stage 2), by which a small apical cell (A)
large basal cell (B) are formed. The apical cell divides into four
cells and forms
a small ball. The basal cell ligates cells at the top (stage 3). The
apical clump of cells grows and forms a spherical ball. The lower part
basal cell stops growing and dividing quite soon (stages 4 and 5).
This part is called the suspensor (C). This stage (5) is called the
globular stage of the embryo.
The apical tissue grows sidewards (stage 6), the
cotyledons (D) are formed from this. At the same time the
tissue between the
cotyledons and the suspensor differentiates into the growing
point of the root (or apical root meristem,
E), the growing point of the shoot (or apical shoot meristem, F) and
the connective vascular tissue (G), stages 7 and 8. The cotyledons grow
and fold out. The seed (e.g. a peanut) is formed.
The seed grows further and goes into rest. It starts to grow again only
when it goes into
the ground and the conditions are favourable for germination.
One might speak of "a double fertilization". First, the pollen
fertilizes the egg, then the seed has to fall or be sown into
the earth. The seed (male) is received by Mother Earth.
processes are visible:
- right from the first division the embryo
- immediately there is cell differentiation, the apical
basal cells are different;
- the tissue is solid.
development of the embryo of a simple animal (e.g. a sea urchin)
At fertilization an egg cell and a sperm cell fuse and create a
(= fertilized egg). After 24 hours the first division takes place: two
equally big cells are created, each being half the size of the
zygote. After that the divisions occur approximately every 12
hours. The embryo is and stays spherical and does not grow. The stage
of 16 to 64 cells is called a morula (= mulberry) (see Fig. 2,
the fifth stage, side view).
Then the cells that lie inside migrate from the centre to the
periphery, some cells die
in the middle and there a cavity is formed. This cavity is filled with
fluid. The embryo is now called a blastula (= small button, Fig.
2, the sixth stage, a cross section) and starts to grow.
The cell divisions in the wall of the blastula continue and then some
cells bend inwards to make a tube to the inside.
This indentation looks as if a finger is pushed
inwards. This happens at the spot that is
called the blastopore (= opening of the vesicle)(Fig. 2, stage 7
and 8). The embryo is now called a
gastrula (gaster = stomach). This indentation-process continues until
the indentation reaches the opposite wall. Then the tissue breaks
open. Out of the blastopore the
anus is formed and the new breakthrough forms the mouth.
these two a tube is formed that will become the digestive tract.
Between the digestive
tract and the outer wall or skin, a body cavity is formed in which
clumps of cells
(the mesoderm) are formed out of which the organs will develop.
Three types of
tissue are formed:
outer membrane or outer skin, or
ectoderm (ecto = outside and derma = skin, blue)
inner membrane or inner
skin, or entoderm (also called endoderm; ento = inside, green)
- and between
them a cavity in which there is in-between tissue or mesoderm (mesos =
These three tissues
are called the three germ layers. Later on all tissues and
organs will grow out of them.
Two cavities came
processes are visible:
- the digestive tract; an external
cavity created from the outside a bit of the outside
world in the body, which stays in contact with the world outside
through the mouth and the anus and
- the body
cavity; the cavity between the skin and the digestive tract. This
cavity has no connection to the world outside. In this
cavity all organs and the centre of the body will develop.
- in the beginning there is no growth,
- in the beginning there is no cell
- two different cavities are formed.
between plants and animals
The embryonic development of plants and animals is different. Plants
show immediate growth, animals do not at first. The cells of
immediately, whereas this is not the case with animals. Plants are
solid and animals have two body cavities. Animals bend inwards and
make a body cavity and plants do not form an inner space.
This can also be seen later on. Plants grow on the ends of
their twigs, their shoots and roots directed to the surroundings. The
growing points are always placed at the ends of twigs, stems and roots,
in the periphery.
Processes take place on the outside. Growth-rate and size are largely
determined by the environment. A plant on poor sandy
soil grows less
well than a plant on nutrient-rich clay. Plants are in the
Animals grow to a certain
(somewhat variable) size and then stop growing. They are not influenced
by the environment as much as plants. Plants are fixed in
the earth, animals can move. Plants do not have an inner cavity nor a
centre, animals do (the heart). Animals have developed an
interior space, in which
processes take place and they have an inner life. See Fig 3.
In anthroposophy the inner life of animals is linked to the
inner space of the body cavity. The
cavity is the basis for the astral body, the non-physical body
in which the soul capacities observing
and thinking, feeling and willing
and doing take place. Plants do not have a soul nor body
Plants and animals both have an ether- or vital body. Plants
can grow freely, animals cannot, because they are orientated on
their centre, as shown by the gastrula. In
table 1 the differences between plants and animals are summarized.
||at once, at the
||not at first, later
||digestive tract and
||the inner centre
|levels of being
||physical and vital
||physical, vital and
1. The development of the embryo of the plant
See text for
description. A: top cell; B: basal cell;
C: suspensor; D: cotyledons;
E: root meristem;
F: stem meristem; G: vascular tissue
The first time a technical term appears, the English
translation is given in parentheses.
Figure 2: The
embryonic development of a sea urchin (schematically)
See text for an
explanation. A cluster of cells is formed, in which a
cavity is formed on the fourth day. Then an indentation arises,
which breaks through on the opposite side. The
result is an organism which has a digestive tract and a body
cavity with clumps of mesoderm cells. From the
blastula on cross sections are given. In the late gastrula and
the last drawing, the organism is cut and is half visible. Ectoderm is
green and mesoderm
Figure 3. The
of a plant and an animal (from van der Wal (2003): Hartmann)
has four drawings of the growth- directions in relationship to the
the environment of the mineral, the plant, the animal and man, that are
useful in embryology.
The plant grows up and down from a point (the
meristem points) and then into the periphery - the
air and the soil. The animal grows inwards.
Table 1. Differences between plants and animals