PERILS OF THE OYSTER. 2 27 



we can give at least the nearest approaching to a solution 

 of Sir Thomas Brown's problem, is in the wise observation 

 of M. Moquin Tandon, that 



" The organisation of marine animals is far from being 

 rigorously exact. The creative power seldom or never 

 employed lines perfectly straight ; the preference was 

 always given to curved and wavy lines ; hence the asterias 

 are not constructed with exact geometrical accuracy." 

 The asterias are peculiar to the sea ; they have no fresh 

 water representatives. In fact, if a sea-star be dropped 

 into fresh water it will act as a poison, and the animal will 

 instantly die. Certain species are extremely common and 

 numerous so numerous, indeed, that the sea-board popu- 

 lation cart them away to manure the land. 



"The star-fishes are variously coloured. Some are a 

 greyish yellow, some an orange yellow, others a dull red, 

 or a violet. Their bodies are surrounded by a calcareous 

 envelope, composed of pieces placed side by side, united 

 by fibres. These plates are armed with tubercles and 

 pricks; M. Gaudry found more than n,ooo of them on a 

 red star-fish that species which is most common in 

 Europe. The asterias have a mouth at the centre of their 

 lower surface. There are also upon this under surface 

 globular drop-like protuberances, which are furnished with 

 arm-like appendages ; and it is from the globular projec- 

 tions that the organs are put forth, which are really the 

 feet of the creature. These form a double or quadruple 

 row ; they consist of a fleshy cylinder of a greyish colour, 

 and in most cases are terminated by a little globular 

 vesicle filled with a watery liquid. This vessel is capable 

 of great extension. When the creature wishes to push out 



its foot, it causes the globular vessel to contract ; this 



H 2 



