340 THE INHABITANTS OF THE SEA. 
number of which, when they are complete, is always a multiple 
of five. They all have the power of changing their shapes in 
the strangest manner, sometimes elongating themselves like 
worms, sometimes contracting the middle of their bodies, so. as 
to give themselves the shape of an hour-glass, and then again 
blowing themselves up with water, so as to be perfectly globular. 
The great Sea-cucumber is the largest of all the known 
European species, and probably one of the largest Cucumerve in 
the world, measuring when at rest fully one foot, and capable 
of extending itself to the length of three. Under the influence 
of terror, it dismembers itself in the strangest manner. Having 
no arms or legs to throw off, like its relations the luidia and the 
brittle-star, it simply disgorges its viscera, and manages to live 
without a stomach; no doubt a much greater feat than if it 
contrived to live without a head. _ According to the late Sir 
James Dalyell, the lost parts are capable of regeneration, even 
if the process of disgorgement went so far as to leave but an 
empty sac behind. Considering the facility with which the 
sea-cucumber separates itself from its digestive organs, it is the 
more to be wondered how it tolerates the presence of a very 
remarkable parasite, a fish belonging to the genus Fierasfer, 
Fierasfer. 
and about six inches long. This most impudent and intrusive 
comrade enters the mouth of the cucumber, and, as the stomach 
is too small for his reception, tears its sides, quartering himself 
without ceremony between the viscera and the outer skin. The 
reason for choosing this strange abode is as yet an enigma. 
The Holothurice, which in our part of the globe are very little 
noticed, play a much more important part in the Indian Ocean, 
where they are caught by millions, and, under the name of 
Trepang or Biche de mer, brought to 
the markets of China and Cochin- 
China. Hundredsof praosare annually 
fitted out in the ports of the Sunda 
Islands for the gathering of trepang; and sailing with help-of the 
Eatable Trepang. 
