THEIR LIFE AND AFFINITY. 24:7 
One thing, however, we know with certainty, namely, that the human 
body, like that of other animals, has its origin in the egg. But the egg 
itself must be considered as the original animal, as the infusorial crea- 
ture, appearing in the globular or primary form of animal life, and, like 
the seed of the plant, containing deadly within itself the whole ani- 
mal, which, under given external circumstances, it develops really out 
of itself. Recent observations have shown that the first rudiment of 
the embryo is formed on the inner surface of the hollow globe of the 
egg, by folding or turning inwardly a part of the integuments of the 
egg; which reminds us distinctly of the purely vegetative bladder-worm 
(Cysticercus, see p. 244), in which the so-called head, or the absorbing 
orifice, is turned inwards. It is plain therefore that we must consider 
the egg in this first period of development also as a plant with a root 
turned inwards (see p. 243); and we find this moreover confirmed by 
the functionary attributes of its parts, since the first introversion of the 
integument forms the cavity of the stomach and the intestines, as the first 
rudiment of the embryo. On the other hand, the external covering of 
the egg being somewhat similar to the green (breathing) surface of the 
plant, performs the breathing function of the embryo, and contains also 
(as the latest observations of Pander have shown), in the external envelop 
of the cuticle, the origin of the organs of sensation. Ina further stage of 
development we see the activity of formation concentrating itself more 
in the point turned inwards, and thus producing new opposites. The 
rudiment of the embryo repeats the above-described form, and the higher 
animal organs, which commence with the spinal marrow and the vertebral 
column, originate above the germ of the intestines of the cavity of the 
stomach. It is now in particular plainly seen how the animal is as it 
were transformed from a plant into an animal in the manner above de- 
seribed (p.234). For at the very first the intestines are only attached to 
the foetus, that is, the gut lies as yet in the umbilical cord, just as at first 
the root is attached to and not in the plant; but the intestines are soon 
afterwards drawn more and more inwards, and by degrees are completely 
enveloped by the animal organs, which grow simultaneously forwards 
on both sides out of the vertebral column; and here for the first time 
the foetus presents the appearance of an independent animal organism. 
The vascular system, however, is much more slow in connecting itself 
perfectly with the foetus; since it is rather a general connecting me- 
dium in the vegetative sphere, and therefore performs the function of 
a bond of union between the integument of the egg and the foetus so 
long as it remains inclosed in the egg. Even at this period of deve- 
lopment the relation of the parts of the egg reminds us of the plant; 
as the foetus, by means of the umbilical cord, is united to the placenta 
and integuments of the egg, held in organic connexion with the ma- 
ternal organism, just as the flower (which it resembles in respect to the 
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