SERTULARLULE : PLUMULARIA. 93 



late form, with the rim cut into about 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 produced both from the main stalk and pinnae, 

 are shortly pedicellate, and resemble a swollen pod girded round 

 with from five to nine 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 containing an opaque elongated body 

 in their centre. Fig. 15. The form of this 

 central body varied in different ova, but it 

 was generally somewhat hammer-shaped. 

 Neither the general mass of the ovum, nor 

 this central body, were seen to move." Dr. 

 Coldstream, June 10, 1833. Polypes " mi- 

 nute, delicate ; tentacula 10, annulated ; mouth infundibuliform." 

 D. 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 

 offshoots 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 spe- 

 cimens of PI. falcata, or Sertularia argentea, of which the family 

 may consist of 80,000 or 100,000 individuals. It is such calcula- 

 tions, always underrated, that illustrate the "magnalities of Na- 

 ture," and take us by surprise, leaving us in wonderment at what 

 may be the great object of this her exuberant production of these 

 " insect- millions peopling every wave." 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, hut 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, ' the depth ! ' '' Montgomery. 



