278 Mr. Home on the Teredo Gigantea 
collection another store was opened to me of specimens pre- 
served in spirits. 
These opportunities, the able assistance of Mr. Clift, who 
has been indefatigable in making the drawings, and the aid of 
Mr. Brodie, have enabled me to draw lip the following ac- 
count of the teredo navalis. 
The teredines preserved in salt water lived for three days 
after being brought to town, which gave me an opportunity 
of making observations upon them. When the surface of 
the wood was examined in a good light, while only an inch 
in depth in sea water, the animal was seen to throw out some- 
times one, at others two small tubes. When one only was pro- 
truded the other almost immediately followed it. One of these 
was about -§ of an inch long ; the other only half that size. 
When the largest was exposed to its full extent, there was a 
fringe on the inside of its external orifice, of about twenty 
small tentacula, scarcely visible to the naked eye : these were 
never seen except in that state ; for when the tube was re- 
tracted, the end was first drawn in, and so on, until the whole 
was completely inverted : and therefore in a half protruded 
state it appeared to have a blunt termination, with a rounded 
edge. The smaller tube was not inverted when drawn in. 
These tubes, while playing about in the water appeared at 
different times to vary in their directions, but usually remained 
at the greatest convenient distance from each other. The 
largest was always the most erect, and its orifice the most 
dilated : the smaller one was sometimes bent on itself with its 
point touching the wood. 
Jn one instance where a small insect came across the 
