THE GLOW-WORM NEREIS. 
531 
The Lug-worm has some of the habits of the tube-making annelids, for, although it is 
perfectly free and able to move where it likes, it does not push its way through the sand at 
random, but forms a tunnel of moderate strength, through which it can pass and repass at 
pleasure. As it bores its way through the sand, it pours out a small quantity of the glutinous 
matter which has already been mentioned in the Terebella, and thus cements the sides of the 
tunnel together in a manner somewhat resembling the brickwork of a railway tunnel. Like 
that work of engineering skill, moreover, the tube of the Lug-worm cannot bear removal, 
^breaking up when it is unsupported by the surrounding earth. It is, however, amply strong 
enough for its use, and will withstand the beatings of ordinary waves without yielding. 
In the whole of the genus Arenicola there are no eyes nor jaws, and the head is not distinct. 
Several species of this genus are known. 
The Gkeat Eunice ( Eunice gig anted) is another annelid closely allied to the Nereidse. 
In this family the body is very long and composed of numerous segments. The proboscis has 
at least seven, and sometimes nine pairs of horny jaws. Sometimes it will attain a length of 
more than four feet, and comprise upwards of four hundred segments in its body, each segment 
furnished with its paddles, some seventeen hundred or more in number. 
When in a living state, this is a most lovely creature, winding along its serpentine course 
with easy grace, and gleaming with all the colors of the rainbow as the sunbeams fall on its 
polished surface and active propellers. 
An example of the beautiful genus Nereis is now given. The Nereidse have both tentacles 
and eyes, and the proboscis is large, often being furnished with a single pair of horny jaws. 
In the typical genus the eyes are four, arranged in a sort of square, and the tentacles are four 
in number. The proboscis is thick, strong, and armed with two jaws. 
The beautiful Nereids are found plentifully on European coasts, mostly hiding under 
stones and rocks, or hiding in the sand. They are well worthy of examination under the 
„ microscope ; and, perhaps, the best method of making out the structure of these beautiful 
creatures is by taking a single segment and noticing its construction. On the back are seen 
certain tufts of different shapes in the various species, but all agreeing in being composed of 
numerous blood-vessels ramifying in a most complicated manner. These are the gills, or 
branchiae, of the Nereis. 
On each side are seen the organs of locomotion, sometimes consisting of a single, but 
mostly of a double, row of oars. Each oar is formed of a strong muscular footstalk, from the 
extremity of which proceeds a bundle of stiff bristles and a variously formed flap, which is 
technically called the “cirrus.” If the bristles be examined separately, their wonderful 
forms cannot fail to attract admiration. They no longer appear as the simple hairs which the 
naked eye would assume them to be, but are transformed, as it were, into a very arsenal of 
destructive weapons, the barbed spear — the scimetar, the sabre, the sword-bayonet, and the 
cutlass, all being represented ; while there is no lack of more peaceful instruments, such as 
the grapnel, the sickle, and the fish-hook. 
The Nereids will live for a time in a shallow basin half filled with sea water, and are, 
therefore, valuable to those who really desire to study for themselves the beautiful forms with 
which they are surrounded, and which, but for the microscope, would ever be hidden from 
our eyes. The observer should not fail to examine the formidable proboscis with its terrible 
jaws. While the worm is at rest, this proboscis is retracted like the finger of a glove, and the 
jaws appear to be situated In the neck, where, indeed, they were once taken for a gizzard. 
But either by dissection or applying pressure in the right direction, the jaws can be drawn 
out, and are then found to be destructive weapons at the end of the proboscis. Many years 
ago, while examining, for the first time, a Nereis which I had found on the sea-shore, I took 
this structure for a gizzard, and find, on reference to my note-book, that a sketch of these 
internal jaws is marked with the title, “ Gizzard of the above.” 
There are very many species of these interesting worms, among which we may mention 
the Glow-wobm Neeeis (. Nereis noctiluca ), a little species seldom more than an inch in 
length, but which is remarkable for its power of emitting phosphorescent light in a manner 
