144 
Z. HYDROIDA. 
Plumularia, 
tween every pair of pinnae. Pinnae alternate, close, parallel, celluli- 
ferous on the upper side ; the cells separated by a joint and set in a 
sort of indentation in the stalk. They have been aptly compared by 
Ellis to the flower of the lily of the valley, being- of a campanulate 
form with the rim cut into eight equal teeth, while in front there is 
a stronger spinous process which does not project beyond the cell. 
The ovarian vesicles are large and remarkably curious : they are pro- 
duced both from the main stalk and pinnae, are shortly pedicellate, 
and resemble a swollen pod girded round with from 5 to 9 cristated 
ribs or bands proceeding from a dorsal tube, and rising into short 
spines on the anterior margin. When recent “ they are translucent, 
and six or seven dark oval masses can be seen within each. These 
seemed to be ova. The vesicle being torn up, and the ova allowed 
to escape, they were seen to be in form irregularly oval, but contain- 
ing an opake elongated body in their centre. (Fig. 6, p. 48.) The form 
of this central body varied in different ova, but it was generally some- 
what hammer-shaped. Neither the general mass of the ovum, nor 
this central body were seen to move.” Dr Coldstream , June 10, 
1833. — Polypes “ minute, delicate ; tentacula 10, annulated ; mouth 
infundibuliform.” Dr Coldstream. 
“ Each plume,” says Mr Lister in reference to a specimen of this 
species, “ might comprise from 400 to 500 polypi and a specimen, 
of no unusual size, before me has twelve plumes, with certainly not 
fewer cells on each than the larger number mentioned, thus giving 
6000 polypes as the tenantry of a single polypidom ! Now many 
such specimens, all united too by a common fibre, and all the off- 
shoots of one common parent, are often located on one sea-weed, the 
site then of a population which nor London nor Pekin can rival ! 
But PI. cristata is a small species, and there are single specimens of PI. 
falcata, or Sertularia argentea, of which the family may consist of 
80,000 or 100,000 individuals. It is such calculations, always un- 
der-rated, that illustrate the “ magnalities of Nature,” and take us 
by surprise, leaving us in wonderment at what may be the great ob- 
jects of this her exuberant production of these “ insect-millions 
peopling every way.” But 
“ So He ordain’d, whose way is in the sea, 
His path amidst great waters, and his steps 
Unknown; — whose judgments are a mighty deep, 
Where plummet of Archangel’s intellect 
Could never yet find soundings, but from age 
To age let down, drawn up, then thrown again, 
With lengthened line and added weight, still fails ; 
And still the cry in Heaven is ' O the depth’ !” — Montgomery . 
