18 ZOOPHYTES. 



feebler, so that frequency represses luxuriance. The succeeding head 

 never inherits the exuberance of parts and the ample dimensions of its 

 precursor. The swelling clusters of the ovarium are never regenerated, 

 nor are they followed by other than simple rudiments, unless in the rarest 

 instances. Scarcely more than mere ovarian protuberances are repro- 

 duced in confinement. The extremity of a stalk having been injured about 

 the 9th of January, after losing its head, subsequent enlargement of long 

 continuance there was remarkable. At last, a fine new head protruded on 

 the 9th of March, surpassing the vigour of any regeneration previously ob- 

 served. Besides 34 or 35 tentacula, regenerated clusters were indicated 

 in three days, by three rows of protuberances, some of them developing 

 into bunches of five cysts, before the fall of this new head, which subsisted 

 nine days. Here the pouch or stomach, guarded by numerous oral palpi, 

 was much distended. — PL II. fig. 11. 



There seems, on the whole, a progressive diminution of the reproduc- 

 tive energies amidst great irregularity in their exhibition. 



Although the earliest animated condition of the tubularia is recognised 

 under considerable analogy to the hydra proper, its race is not perpetuated 

 after a similar mode, namely, by external germination ; nor do I know any 

 of the zoophytes where the polypus or hydra is combined with other parts — 

 where multiplication by the young issuing immediately from the parent's 

 body, though often very near it, augments the species. 



Pith, or Medullary Matter. — The casual observer may be prone to 

 conclude that vitality resides throughout every portion of the stem of the 

 tubularia, because experiment can produce superabundant organization, 

 that a greater number of essential living parts shall result from artificial 

 interference than are allotted by nature amidst her undisturbed operations. 



The stalk of fine and florid specimens is replete with a yellowish 

 tenacious mucous matter, completely occupying the whole, or accumulated 

 in irregular ruddy masses, separated by transparent intervals denoting va- 

 cuity. Sometimes a surprising discharge issues from the headless summit 

 above, or from the ruptured root below, when torn off its foundation ; and 

 sometimes continuing to flow for several days froni either. We know nothing 

 farther of this substance than that its presence shows the healthy state of 



