124 Animal Life 
and handsome meduse, which are such conspicuous 
and familiar objects of the summer sea. 
Almost as remarkable and interesting have the 
ree moss animals or bryozoa proved to be, with their 
: = Qe) a ancient lineage going back into dim geological 
= : — ages, and their wonderful habit of living together 
= : in great colonies which increase by a singularly 
_ § z plant-hke budding process. They are the most 
© ee ~~ sociable creatures, the little cell that forms the 
4 : home of each individual member of a colony being 
» : ) co generally connected on all sides to similar cells, so 
: that the inhabitants can stand at them front doors 
Pee and talk together with ease, which is fortunate for 
them as they are unable to quit their respective 
Se a houses. 
cTS ni ira Gok Sora ee Ae What a surprise the man who first examined 
after its escape from the nursery. a living colony of the sea-mat bryozoa under the 
microscope must have had. First he saw nothing 
but the famihar slightly oblong cells, which remind one of a number of round-toed shoes 
placed as close together as they will go in the neatest order imaginable. Then gradually 
from out each cell a circle of tiny arms or tentacles began to protrude, and when fully 
extended to bend about in all directions, transforming what only a few minutes before 
was an apparently imanimate object, into a dense crowd of active waving tentacles. 
As there are on an average 1,800 cells to the square inch, each tenanted by a 
tentacle-crowned animal, some faint idea may be gathered of what a mass of waving 
arms are to be seen when a colony is in full swing of work. The average sized 
bunch of fronds which comprise’ an entire colony of the sea-mat bryozoa, has been 
estimated. when in full vigour to have a population of 18,000 individuals. 
Hach tiny member of this colony works for the common good, for they have a 
nervous connection with~each other and probably a kind of general circulation throughout 
the whole colony. What represents the head of each animal, is crowned with a circlet 
of tentacles clothed with very minute but strong hairs or cilia. The hungry, eager 
little mouth is in the midst of the tentacles at the bottom of the circlet and leads 
to a tiny gullet and stomach. When the creature 
is hungry it protrudes its head from out the little 
opening at the top of the shoe-like cell, the graceful 
tentacles are expanded and, together with the hairs 
which clothe them, begin to wave about with a 
regular motion, causing a miniature whirlpool 
current to arise. In this whirlpool the various 
small animal and vegetable organisms on which 
the creature feeds become entangled and carried 
down by the current into its hungry mouth. 
Though the sea-mat bryozoa is curious and 
interesting enough to watch through a microscope, 
it is nothing to the astonishing and truly mar- 
vellous sight which is revealed by that instrument 
when a living colony of the “ Bird’s-head” bryozoa . , 
is placed in the field. Not only the now familiar ie 
tentacles are to be seen waving in all directions, ES alt tenant Oe 
5 é s p formed. Note the circular door through which 
but from the outer side of each cell rises a they escape. 
