Brain PHystoLoGy oF Worms 357 
The specimens of Cerebratulus which I used in my 
experiments were over 50 cm. long and almost as thick as 
a finger. The layman would readily have believed that he 
was dealing with an eel instead of with a worm. The ani- 
mal lives in the sand. If it is laid upon the sand-covered 
bottom of the aquarium it soon buries itself in the sand. If 
the head is amputated from such an animal the head-piece 
continues to bury itself in the sand when it is not too short. 
The body, on the other hand, does not make a single attempt 
to bury itself in the sand. 
IV. EXPERIMENTS ON ANNELIDS 
The Annelids possess besides a fairly complex brain a 
chain of ganglia which transverse the entire length of the 
body. We have the experiments of B. Friedlander and of 
Graber on the function of the central nervous system of the 
Annelids. 
Friedlander’ amputated the anterior and posterior seg- 
ments from angleworms. 
The latter conduct themselves, to put it shortly, as normal ani- 
mals: they soon bury themselves in the earth. Not so the beheaded 
worms. Immediately after the operation they execute violent 
winding motions, perhaps creep about for some time, but usually 
come to rest after a short time, and can now remain quietly upon 
moist earth covered with moist filter paper, for days and weeks 
without, apparently, making any autonomous movements after the 
wounds have healed. Every stimulus however soon awakens them 
from their passive condition. They then move about energetically, 
even creep some distance, but soon fall back into their original 
lethargy. 
The second series of experiments of Friedlander consisted 
in excising a small (5 to 10 mm. long) piece from the abdomi- 
nal nerve-cord of angleworms. Friedlander had expected 
that the two portions of the worm lying anterior and posterior to 
the operated point would conduct themselves physiologically during 
1 Biologisches Centralblatt, Vol. VIII. 
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