, 1891-05-09

have enlarged on the evidences OF design
manifest in the textural conformation of
such a shell as the Cones. But we have
changed all that nowadays, and no one
who wishes to be thought abreast Of the
science OF his generation would venture to.
say much on such II pOiut, lest he should
be accused of setting at naught the great
Goddess Evolution, whom all Science and
the Age worship. 1t is true that one
need not become an atheist because he is
an advanced ev0lutioniSt. He need not
lose his belief in Il Creator because he
EhlnkS he knows the plan and the means
whereby all things were created. He may
De able to swim with Tom to the Other
END OF Nowhere aud see Mother Carey
sitting in eternal repose and making new
things out of old by letting them make
themselves. This is doubtless a phase of
many sided Truth but it does not tell the
whole truth as it appears to the modern
teleoIogist. He still maintains that things
were ~designedly fashioned in Nature, how
ever such fashioning may have been effect
Ell, to serve definite purposes, and that the
invisible Creator" and CHS eternal power
anu godhead" are clearly manifest in the
Things that are made; or, to quote Millions
"Dimly seen
In these his lowest works yet
declare these
His goodness beyond thought and
power divine
I confess myself a disciple of this school,
holding such opinions with respect to the
doctrine Of Evolution as have been taught
Ey my old master, Goodsir, Professor
Owen, and Hugh Miller. In the structure
Of the Cone, as revealed by the micros-
cope, | recognise a picture from what
LOngfellOw calls ''the stOry-bOOk Our
Father has written for us"-the story
book whose every page tells of His infinite
wisdom and power.
The internal layer of the shell is secre-
ted by the ~visceral fold of the mantle.
This may account for the greater dellcacy
and simplicity of the coating OF the inner
surface and lips OF shells. They are uSu-
ally smooth and polished and often nacre-
Gus. This nacre, or mother of pearl, owes
its irridescent brilliancy to u zig gag
wavy wrinkling Of the internal layer. 1t
has been successfully initiated by art,
but the exact way in which the w~rinkling
is effected by the vital processes of the
creature is not understood. The nacreous
layer is Of the simplest description, being
only what is called by anatOmistS a base
ment membrane thickened and hardened
With carbonate of lime. This diagram
exhibits it's appearance under the mIcros.
cope.
Pearls are Jumps Of pacre generally
glObular or OvOid, but assuming various
shapes when artifcially induced loosely
embedded in the flesh Of the MolIu~c or
attached to the mother of pearl lining Of
the valve and caused by the irritatiAn Of
the mantle by wound, the presence OF an
ahOrtiye egg, o" the in5y"tlnctioa OF y
foreign body. Here is u specimen 'tixed
to the valve of an Avicula from the Fort:
The subject Of Pearls would suffice for q
lengthy and interesting discourse by itself.
| do not propose to deal with it at all TIL
we come, in a subsequent lecture, to the
consideration of the West Indian pearl pro-
ducing shell-fsh.
In looking at a promiscuous Lot OF shells,
one notices much difference in the texture of
different sorts, apart from their microscopic
structure, though of course dependent on it.
To express these general external appearan-
ces, conchologists are in the habit of using
such terms as porcellanous or crystalline,
concretionary or granular, vitreous, and
corneous. These words explain themselves.
Here are examples from this Island. Cardi.
UNI subelongatum of the concretionary
Olivia reticularis, porcellanous; Amphibulina
patula, horny and a beautiful little Bulla; of
the CLASSY type.