The Sooutk Justralia?! Naturalist. 
141 
borers had the problem of food supply solved by the circulation 
of the sea water, containing minute organisms and minerals, 
through an Inhalent siphon. After the creature had extracted 
what It needed the purified water was expelled by the outgoing 
siphon. In this way these tiny creatures helped to maintain the 
health and purity of the sea. The Teredo N avails, or so-called 
“shipworm,” was really a mollusc with a bivalve shell to protect 
its vital organs. The ravages of this organism had been noted 
from earliest times. It made its home in wood, and lined its bur- 
low with a calcareous tube, 7'he hardest wood was not Immune 
from its attack. Redgum w^as the most resistant. Two species 
were found in South Australian waters, four near the Victorian 
coast, and 30 to 40 had been identified in American seas. Adany 
endeavours had been made In recent times to combat the devas- 
tation wrought by the teredo. Copper sheathing and iron nails 
arrested their ravages to some extent. In the United States of 
America the use of chlorin gas produced by electrolysis of sea 
watei, by the agency of a floating electric battery, had proved suc - 
cessful for a time. It was not wuse to keejf5 jetty piles too clean, 
for the presence of Seipulae and accumulations of seaweed warded 
off the attacks of the borer. IT.e Teredo had to Its credit the 
rapid destruction of floating timber which might otherwise prove 
a serious danger to shipping. 
. lecture was illustrated with blackboard diagrams and sec- 
c -Bay jetty and timber from the wreck 
of the Star of Greece, near Willunga, riddled by these “white ants 
of the sea. 
Di. C. Fenner followed with an Instructive talk on some of 
the commoner minerals. Referring to Mr. Kimber’s allusion to 
the tunnels bored m the columns of the Serapeum, the doctor said 
that these supp led conclusive evidence of the alternate slnkino- 
tht ^ t “""‘y under wate? 
nat the boung mollusc could work. The swamps at Port Wake- 
-leld, too, might be cited as proof of this change of level Fverv 
A" crystalline form, even 
tli speefes of a fugles of its prisms determined 
sis Tlk M I ‘^*'1 chemical analv- 
sis. Ihe iMount Lofty Range consisted largely of quart:^ The 
^stals were composed of a six-sided prism topped b a pyran U 
of the same number of faces. A close examination revealed trme 
or scratches, across the faces of the prism. These wetoexpS Oed 
