POLYPES. 
63 
tatingly pronounce them eyes, and so they are considered 
ky some eminent physiologists. Others, however, con- 
sider them to bear a closer analogy to our organs of hear- 
ln g, the crystalline globule (or otolithe ) being, as it is 
stated, capable of vibration within its vesicle. Whatever 
tney be, the same organs aro found, in the same form, in 
tnat class of animals just alluded to, the Jelly-fishes or 
Medusse. 
The disk is endowed with an energetic power of con- 
traction, by which the margin is diminished, exactly like 
tnat of a Medusa in swimming ; and the tentacles have 
a so the power of individual motion, though in general 
his is languid, their rapid flapping being the effect of the 
contraction and expansion of the disk just mentioned, pro- 
ducing a quick involution and evolution of the margin, 
and carrying the tentacles with it. Occasionally, how- 
ever, all the tentacles aro strongly brought together at 
heir tips, with a twitching, grasping action, like that of 
fingers, which is certainly independent of the disk 
The phenomena, of which an example has been given 
so 1S pa P er -' have almost as greatly startled the philo- 
tion f ° f0Ur ag6 ’ aS th ° Se connccte d with the rcproduc- 
As ' ° u & astonished our ancestors a century ago. 
cule'd the f0rmer case > the y were disbelieved, denied, ridi- 
found C ° n f med > belicved > wondered at, and at length have 
as the T ^ aCG amon S tbo recognised laws of organic life, 
come to UV 01 J ^^ crna ^ on Generations. When we 
occasion t S ^ ea ^ ^ be Medusae as a class, we shall have 
may state° to tbe to P ic a o ain 1 for tlie present we 
amono- m ’ 1&t tte order described is found to prevail 
° an ^ s P ec ies and genera of the marine Polypes. 
