HE MEDUSA. I4I 
fremity, or along the whole length of the fine tentacles. These 
cells are made of a double semi-transparent membrane, which 
is very thin and somewhat flexible; within the cavity there is 
found a long thin thread, coiled up upon itself when the sting is 
inactive. This thread can shoot out of the bag, and then there 
is seen at its extremity one or more sharp points like darts. 
These microscopic poniards are most probably tubular, and along 
the canal the poison issues from the gland. It is with these little 
stings that the medusz, whose tissue is so delicate and so weak, 
A BEROE, 
(Berce ileus.) 
and whose intelligence is so obtuse and so limited, can defend 
themselves, and even attack. The smarting sensation which they 
cause when touched is violent, their sting producing a blister, and 
an irritation which lasts for days. 
The Medusa of Aldrovand (Rhizostoma Aldrovandi), whose 
habitat is the Mediterranean, and the Medusa of Cuvier, which is 
found in the Straits of Dover, also possess a stinging apparatus, 
which produces an inflammation. We are told that one drop of the 
poison will inflame the whole of the muscles of the eye, and raise 
upon the hand pustules which itch intolerably. It is in this class 
of acalepha that naturalists place the Beroes and the Velelle. The 
beroes are ovoid or globular bodies, whose sides are ornamented 
with teeth-like points and filaments. Sometimes the sides form 
a kind of wings. Certain of the beroes resemble castles without 
