ORGANIZATION AND GrRowTH 201 
nally lay opposite de, and from the lower cut end « of the 
stem. When the new stem had attained the length de, 
I turned the whole animal about its axis, so that b and e 
were directed downward, and the specimen was in the posi- 
tion indicated in the drawing. The stem de ceased to grow, 
and a delicate root W,, growing downward, was formed at 
e. The drawing was made soon after the root began to 
grow. Besides being formed at e, roots W, also grew from 
the apical cut end 6 which was directed downward; the three 
stems S,, S,, S,, were formed upon the upper surface of 
the stem with their corresponding roots W,, W,, W,,. 
5. In all these experiments one fact—which is, however, 
not a specific property of Antennularia—constantly repeats 
itself: new growths arise much more easily and numerously 
from the basal than from the apical end. I have observed 
the same fact in Actinia mesembryanthemum, and A. von 
Heider mentions it in connection with Cladocora.’ 
In general, too, the formation of roots in Antennularia is 
dependent upon the formation of a stem. If a stem is 
formed at any point, roots also form after some time, at first 
upon the under surface of the old stem, then upon the upper 
surface in the immediate neighborhood of the new stem, 
and finally at the lower end of the new stem itself (Fig. 40). 
It is self-evident how such phenomena complicate the 
influence of orientation upon the place where new organs are 
formed. 
6. I cannot say precisely how the position of the new 
organs formed in Antennularia is determined by the orienta- 
tion of the animal toward the center of the earth. Naturally 
the effect of gravitation cannot be different in animate from 
what it is in inanimate nature, and there would be no reason 
for being disappointed should it be found that the apparently 
mysterious effect of gravitation upon organization in Anten- 
1A. von HEIDER, Wiener Sitzwngsberichte, Vol. LCCCIV, Part I (1881), p. 664. 
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