be formed of circular muscles, press on the fluid contain*^ 
within the polype and force the weakest part, and conseque . 
ly the creature ascends through the mouth of the cell , a ^ 
Dr. Farre thinks that the stomach has a power also ^ 
lengthening itself, and so assisting the protrusion. . 
whatever power produces it, the expansion is very gmt 
As the polvpe lies in the cell, it is drawn into an 8 conl)g u jj 
tion, and thus may be said to be packed away in a very si" . 
compass. It must not be supposed that all the strut, ' , ^ 
here mentioned can be viewed in a single specimen > 
requires a good microscope, good light, and repeated - 
animations; for at first all seems confusion. The p°^j 
pidoms of this order vary greatly in size, appearance “ 
structure. But although there have been reasons to const 
the solid parts of the foregoing orders as organic, an opin' 
which is opposed by many, yet here their organic charac , 
is allowed, and the point need not therefore be enlarg^ 
on. The solid parts are here properly considered to 
continuations of the external parts of the polype. -y 
The arrangement of the horny cells oi the first » al 
varies ; in some they are arranged in parallel com pan' 
like Pan’s pipes, in others in irregular clusters, and in a 
they arc without any definite order. -y 
With the exception of those genera forming the 
Vesiculariadse, already mentioned, the whole belonging 
this order arc either calcareous or membrano-caleai e ^ 
Those species forming the genus Crista bear a K reat .i tf ; 
resemblance in form to the Sertularice, among the HydroW^, 
with which they were formerly associated. They are 
borescent, and the centre of the trunk, branches ar.d 
arc occupied by a vital pulp, from which the polype* J 
developed. The polypes are thus united mlo one co^p 0 
animal as in the first order. The growth of the polyp' ^ 
is also similar in these widely separated genera, ),t 
the reproduction is also by ovarian vesicles, nothing c „»l 
be more natural than associating them together, it ext js 
characters alone were to be our guide; but the a o<l 
widely different. The terminations of the branches ^ 
new cells are closed, but as developement advances^,, 
cells open, in a precisely similar manner to what has , 
noticed while speaking of the Hydroidte. When the P"l ij 
effected an advancement to the extent of an intern a pU 
stops for a short period, and what was semi- mem hr anon 
pellucid becomes white- and solid by the deposition o ^ 
reous matter. But those parts which are membra no^pi 
pellucid while the creature is living, become alter j( ,p 
very solid and brittle, arising probably from the cr ^, , a ‘ th e 
of the calcareous particles, as soon as they are freed 
