88 HISTORY OF BRITISH ZOOPHYTES. 
the softer extremities vegetating downwards, and remaining 
susceptible of adhesion, it becomes invested by exposure with 
an imperceptible epidermis. All nascent Tudularie are of 
the palest grey; and for the first fortnight the length of the 
tentacula, and general dimensions of the hydra, are propor- 
tionally greater than in adults. But the stem is seldom 
straight ; sometimes also irregularities are seen near the 
root, which has no radicles. ‘The head of the nascent 7u- 
bularia falls after an indefinite period, just as with the adult. 
But life is so feeble here, that the first is rarely replaced by 
a successor.” After several other interesting observations, 
which our limited space will not allow us to quote, he adds 
—‘ We collect from the preceding detail that an external 
ovarium is situated among the other parts composing the 
hydra or head of the Zudularia indivisa ;—that the unusual 
curvature of the tentacula, their irregularity, and symptoms 
of approaching decay, augment in proportion to its advanc- 
ing maturity, while the aspect of the stomach also indicates 
that its functions are required no longer. It is impossible 
to overlook the correspondence of these conspicuous facts 
with that uniform principle of nature, obviously testifying a 
warmer solicitude for perpetuation of the progeny than for 
the permanence of the parent. How few are the effectual 
