11 
however, appears to me, I confess, doubtful; and Tam rather inclined to 
believe that near the place where the young Polypi appear ما‎ push forth, the 
aperture of the ovary exists, from which the minute oyum having escaped, and 
by means of its gluten adhering to the parent, thus forms a sort of placenta 
from which the,extruded animal draws for a period its vital sustenance. I sus- 
pect that I have detected the aperture or apertures of the ovaries in A رم‎ - 
CRINITES ROTUNDUS, between the angles near the adhesion of the joints of the 
pelvis and costa, as also in the division of INARTICULATA between the scapula. 
Whether the Crinoidea did or did not possess a vent, still remains doubtful. 
Their organization appears to have been such as might, perhaps, have enabled 
them to dispense with this part; since the sphincter muscle at the bottom of 
ihe stomach (the apex of the column) permitted, probably, only those juices to 
pass into the alimentary canal which were destined to be assimilated into the 
system, and matter, not so applicable, may easily have been disgorged by the 
mouth. Even the juices carried into the alimentary canal, too abundant for 
the general recrements needed by the animal frame, may have been exuded 
through vessels between the joints, and have been employed in repairing occa- 
sional injuries, or forming additional lamina to strengthen the fabric. 
The liability to frequent accidents to which animals formed of such numer- 
ous parts as the Crinoidea must be exposed, renders their having a power of 
repairing injuries sustained, and of reproducing portions lost, necessary; and 
that they have this is verified, beyond doubt, by the specimen of Pewracrinus 
CAPUT MEDUSE, recently in the possession of the late John Tobin, Esq. 
"The mode in which the numerous ossicular concretions of these animals are 
connected together by a gelatinous muscular substance only, renders their 
separation after death easily accounted for, and explains the rare occurrence 
of perfect specimens in a fossil state. The formation of all the ossicula by cal- 
carious secretions, furnishes the reason why they have been so perfectly pre- 
served iu the mineral strata, although changed into foliated spar similar to that 
which generally occurs in the remains of Echini and Asteria. 
Where the muscle is preserved, or a portion of the animal oil, however 
minute, intervenes between the fossil and the imbedding substance, or between 
two joints, they easily separate, and if exposed to the gradual action of an 
acid, not unfrequently muscular fibre itself may be developed. 


መጻጻ سس‎ 
