286 Mr. Home on the Teredo Gig ante a 
whether their blood has red globules or not, and whether 
they breathe air or through water. In proof of this it was 
met with by M. Cuvier in the oyster, in the snail tribe, and 
all the mollusques which creep on their bellies.* 
The mode, in which the breathing organs of the teredines 
are supplied with water, makes it evident that all sea worms, 
as well as other soft animals, which have no cavity for the 
reception of sea water, must have the breathing organs placed 
externally. This is the case with all those species of Actinia 
met with in the West Indies, called Animal Flowers ; and the 
beautiful membranous expansions they display resembling 
the petals of flowers, are in fact the breathing organs, not 
tentacula for catching food, as their appearance led me to be- 
lieve, when describing the new species, discovered in the year 
1780, and which has a place in the Philosophical Transactions 
for 1785. 
In animals so perfect in their organs as the teredines, and 
which have red blood, there can be no doubt of the exist- 
ence of brain and nerves : but it is not to be wondered at 
that from the gelatinous texture of the animal they eluded 
every attempt to discover them, in the present investigation. 
There was no material difference in the structure of the 
different varieties that were examined, although they varied 
from each other exceedingly in their size : except that in the 
large one from the British Museum, the heart was situated 
almost close to the origin of the breathing organs. All of 
them had vegetable matter in their stomachs. They must 
therefore all be inhabitants of wood, and belong to one species. 
* Vide Lecons d’Anatomie comparee, Vol. IV. Lee. 27, 
