T H E ' V A S M A NIA N N AT U KALI ST. 
73 : 
is very beautiful as in the sponge called Venus 1 flower basket , and in the 
Glass rof>e sponge, both of which can be seen in the Tasmanian Museum. 
Fig. 5— 
Sponge Spicules. 
Fig. 6 — 
Seh Anemone. 
The next large group is the phylum Coelenterata , which means 
animals containing a simple internal cavity. This internal cavity serves- 
for digesting the food of the animal. The group includes quite a number 
of very different animals as will be seen below. A convenient large but 
simple member of the group is the creature known as the sea anemone 
(Fig. 6), common on the rocks at low-tide at Bellerive Point and other 
places. They are easily noticeable from their high colour and their 
habit of contracting themselves suddenly when touched. A vertical 
section or cut through one is shown in Figure 7. Each animal is really 
a cylinder attached to the rock at one end and leaving at the other a 
ring of arms or tentacles in the centre of which is the mouth. This 
leads to a short tube called the 4 gullet ’ hanging within the animal. Any 
particle of food reaching the mouth passes into the gullet and from, 
thence is transferred to the internal cavity where it is digested. The 
common sea anemones live a solitary life but some of their relatives, 
habitually, live attached to one another in large congregations called 
4 colonies/ and each anemone-like animal is called a zoo Id. Coral is the 
result of numerous colonies of some relatives of the anemone which 
manufacture a lime skeleton from the lime in sea water. Sometimes the 
colony becomes branched and the zooids are fastened here and there to 
a branched stalk. These are called zoophytes (animal plants). In many 
of these there is a partition of the work of the colony ; some of the 
zooids have the function of procuring and digesting the food for the 
colony; others again have the duty of reproducing the colony; still 
others are intended to serve as tactile zooids, feeling the presence of any 
large object near the colony. As an example of this we may take the 
Portuguese 1 man of war * (Physalia) which floats on the surface of the 
water. This consists of a number of zooids attached to the under 
surface of a rather large football-like float which is merely the expanded 
end of the hollow axis connecting them. Some of the zooids procure 
the food for the rest, some act as feelers and some have connected with 
them long fine strings which contain stinging cells. When these strings 
come in contact with an object they discharge minute arrow-like darts. 
