ACTIVITIES OF COLONIAL ANIMALS 349 
in accordance with the injection used, were slowly discharged 
from the mouths of many of the autozodéids. 
If a strong solution of methylen blue in sea-water is injected 
into an expanded Renilla, in a very few minutes the colored fluid 
may be seen in one or more of the eight mesenteric chambers of 
the autozodids and even in the tentacles connected with these 
chambers, and in a very short time the solution may be dis- 
charged as a blue cloud from the mouths of these zodids. These 
several lines of observation make it perfectly clear that the auto- 
zooids of Renilla may discharge from the colony to the exterior 
both solids and fluids. 
In a similar way inward movements may be demonstrated in 
these zodids. If a very small piece of crab meat is dropped on 
the mouth of an expanded autozodéid, the tentacles quickly close 
over it and it is passed into the oesophagus. The distal half of 
the zoéid then contracts slowly but vigorously like a sphincter, 
and the bit of meat passes very gradually through the proximal 
half of the zoéid till, in about five minutes after it was placed on 
the lips, it disappears in the depths of the animal. After this 
disappearance the zodid gradually elongates and assumes its 
normal proportions. ‘The operation in this instance, like that 
in the discharge of eggs, feces, etc., appears to depend upon ciliary 
action, but whether in Renilla, as in the sea-anemones, the move- 
ment is due to a reversal of the usual outward stroke of the cilia 
in the region of the lips or whether the food is swept in by the 
normal action of the cilia of the suleus could not be ascertained. 
In any event the autozodid of Renilla can carry solid material 
inward as well as outward through its oesophagus. 
If the distal end of an autozoéid of Renilla is flooded with ecar- 
mine or methylen blue in sea-water, it should be easy to see 
whether inhalent or exhalent currents are normally present. As 
a matter of fact, all tests of this kind failed to demonstrate under 
ordinary circumstances any currents either outward or inward 
at the mouth of the autozodid. If under such circumstances the 
distal end of a zodid is quickly cut off by a single stroke of a pair 
of fine scissors, a momentary outward gush of water takes place, 
during which the beheaded polyp contracts. Presently it re- 
