Wlarvels of the Universe 807 
SEA MATS 
BY EDWARD STEP, F.L.S. 
IF one were content with knowledge 
derived from a cursory superficial 
examination, we should certainly class 
the Sea Mats with the Sea Firs; but 
surface appearances are often de- 
ceptive ; and though the makers of 
the Sea Mats dwell in little cells or 
pockets much after the manner of the 
Sea Firs, a closer study of structure 
and organization shows that they are 
in no wise related or really alike. The 
Sea Mats occupy a position in the scale 
of organization on a much higher plane , 
than that of the Sea Firs. Scientifi- Photo by] LW. West. 
BUGLE CORALLINE. 
cally, they are known as Polyzoa, One of the finest of our native species It is three inches in length, 
from their being found associated in and its chalky stems have elastic joints. 
fixed colonies. In this, of course, they resemble the Sea Firs, but whereas the latter are true socialists, 
each member of the community benefiting from any bit of good fortune that falls to one of them, the 
Sea Mat community is made up of strict individualists, each keeping to himself what he can secure. 
The community is so closely compacted because it owes its origin to a single individual, who emerged 
from an egg and passed through a free-swimming larval stage in which locomotion was made possible 
by its possession of a fringe of short gossamer threads, and by lashing these in succession, it rowed 
itself about. After a time it settled on a seaweed, a shell or a stone, glued itself down, dropped 
its gossamer fringe, and developed a thin, horny crust or cell, with an opening near the top. 
Around its mouth it developed a crown-like circle of tentacles with which it might catch any 
minute creature that passed by that 
would serve as food. 
If we were to cut through one of 
these horny cells and the little poly- 
zoon within, we should find its struc- 
ture to be of a very simple character, 
but still showing a great advance upon 
that of the Sea Fir zoophyte. First of 
all, we should find that the horny cell is 
lined with a soft living bag, and in the 
centre a tube, which hangs down from 
the mouth to about two-thirds of the 
depth of the cell, then suddenly turns 
upon itself upwards again and makes 
exit through the cell-wall a little below 
the mouth and crown of tentacles. This 
U-shaped tube is the creature’s diges- f Has ae ; 
tive system, the lower and most roomy Photo by] [W. West. 
: ; FOLIACEOUS CORALLINE. 
portion forming a sort of stomach. 
A silvery phosphorescent thread that creeps over red seaweeds. It 
To one side of this tube, between the is provided with numerous lashing bristles. 
