430 ALFRED O. GROSS 
Furthermore, this worm is able to adapt itseK to a large range of 
plants for food and utilizes that which is abundant and most 
convenient to its burrows. The jaws and proboscis are used 
extensively in excavating burrows, but, as compared with the 
earthworm, a relatively small amount of sand and mud is ingested 
by Nereis. The animal materials, such as bryozoans, sponges, 
and egg masses, found in the intestine were originally attached 
to the plants eaten by Nereis and were probably an accidental 
element of the food. The worms seemed to exhibit no preference 
for eel-grass covered with bryozoans and egg masses, nor did 
they shun such material when they chanced to come upon it. 
When a number of Nereis are crowded into a small dish they 
may, especially if mechanically or chemically stimulated, vio- 
lently thrust out the proboscis, extend the jaws, and bite the 
body of a fellow worm so severely as to sever it in two parts. I 
have seen a worm bite its own body in two when placed under 
pressure or treated with a strong acid or alkali. In such cases 
it may incidently take into, its proboscis some of the flesh which 
is grasped. Very often, when ejecting extracts of animal juices 
from a pipette toward the head of the worm, it would thrust out 
its proboscis, just as it did when treated with an acid or alkali. 
These thrusts I soon learned were not attempts at securing food, 
but were acts of self-defense and, it is very probable they often 
serve the worms as an effective protection against enemies as 
large or much larger than itself. The feeding response is a much 
more deliberate act. Is it not possible that an observation, 
such as noted above, and the fact that other species of Nereis 
have been reported as animal feeders, may be primarily respon- 
sible for Professor Verrill's erroneous statement, a record which 
has been copied so many times without any attempt at veri- 
fication? 
The jaws, though not used in capturing animal prey, are 
employed in tearing out bits of the plants used as food. In the 
intestines of some of the larger individuals it was not uncommon 
to find pieces of eel-grass or other vegetation 1 to 2 cm. in length. 
A number of experiments were made with the natural food in 
an effort to localize the sense of taste, but the worms showed no 
