168 STUDIES IN GENERAL PHYSIOLOGY 
and a piece of meat to the other, and then threw the whole 
upon the outstretched tentacles of a hungry animal. The 
tentacles which came in contact with the meat reacted at once 
by bending by which the meat was carried to the mouth; the 
tentacles in contact with the paper did not react. I removed 
the thread and reversed the position of the meat and paper 
upon the oral plate, so that the tentacles which had before 
been touched by the paper were now in contact with the 
meat. The tentacles touched by the meat carried it to the 
mouth, while the tentacles touched by the paper let it fall. 
The meat was then crowded into the mouth, and the thread 
was pulled in after it; but the paper and a piece of the 
thread remained outside of the oral opening. No change 
occurred within the next twenty-four hours. After this 
period the thread was ejected, but without the meat. The 
latter had probably been digested. I have often repeated 
this experiment with the same result; only occasionally the 
thread was ejected earlier, and then a piece or all of the 
undigested meat was still attached to the thread. 
I divided an A. equina into two pieces by a transverse 
incision, The oral piece—which I shall.call the head piece 
—had the old normal mouth at its oral end; the body-cavity 
was open also at the aboral end of the head piece, and food 
was taken up here likewise, even though no tentacles were 
present. The old oral mouth of the head piece showed the 
same choice in the taking up of food after the division of the 
animal as before. But the aboral mouth of the head piece 
at times took up paper wads and swallowed them. Yet I 
saw it refuse paper wads while at the same time it eagerly 
took up pieces of crab meat. 
While the old mouth at times refused meat, the aboral 
mouth was nearly always ready to take up food. 
3. The following means, however, served to decrease the 
irritability of the mouth toward chemical and mechanical 
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