CAMPANULARIA. 219 



a fine ruddy hue — whicli seems partly dependent on the food or the 

 season. Those highest coloured are always single specimens, that is, con- 

 sisting of a single bell and hydra, when their numerous long tentacula re- 

 curving over the Up might be supposed in alternate arrangement, or al- 

 most a double row, which is somewhat the character of the preceding 

 subject. In this state the zoophyte is like a beautiful flower. 



The central pith of the twig seems susceptible of contraction and ex- 

 tension by the rise and retreat of the hydra, if it be not an optical illusion. 

 Perhaps something analogous to muscular powers may belong to such 

 minute products. 



This zoophyte is generally meagre ; but it is embellished by the 

 spreading of the hydra over its delicate bell. In most of the Sertularian 

 tribes, the sheath, denticle, or cell, constituting an inorganic part for re- 

 ception of the hydra, remains permanent, but here the bell always falls on 

 the decay of its tenant. The two are mutually dependent on each other. 

 There is a striking contrast between fig. 1, a specimen in vigour, and one 

 where only a number of vacant twigs remain. — Fig. 8. 



That specimen was embellished by about 100 hydras with their trans- 

 parent bells, 70 being on the main stem, and 30 on the branch. All were 

 in the highest vigour, some in ample developement, displaying their lively 

 action, others rising cautiously to spread over the lip of their dwelling, or 

 clasping the tentacula, and suddenly crouching down in retreat below. 

 But their decay was rapid. In 48 hours from the first enumeration when 

 obtained, the whole were reduced to 36, distributed in equal proportion 

 on the stem and on the branch. In another day only 6 remained ; on that 

 which followed no more than one. Most of the bells had also fallen. 



Thus had an hundred living beings perished on the fourth day after 

 visrorous animation. 



Meantime from the same reproductive energies residing in other 

 species, many of the vacant twigs which had previously borne animals were 

 extending, and speedy regeneration ensued. A long clavate enlarge- 

 ment of the growing twig unfolded as a new hydra with its bell. 



Thence it is evident that decay of the bell should be concomitant 

 on the decay of the hydra. It is part of the arrangements of Nature. 



