Home » categories » rare book library » Catelle. The Pearl.
This chapter is tagged (labeled) with: 

Ch. 8: Genesis of the Pearl

Ch. 8: Genesis of the Pearl Page of 358 Ch. 8: Genesis of the Pearl Text size:minus plus Restore normal size   Mail page  Print this page
GENESIS OF PEARLS
as a baroque. The rounding action of the mollusk is clearly shown in these excrescences, as the borer is not simply covered and levelled with the shell, but the slight elevation above the level of the lining receives a continuity of concentric deposits which finally raise it very considerably above the surface and separate it in construction from the lining to which it is attached. The shell herewith reproduced illus­trates the result. Borers pierced it at the thick part of the hinge, and burrowing down, entered the interior at the point where the baroque is shown. In rare instances, pearls attached to the shell do escape the concentric deposition, for they have been found buried under even layers of nacre, when the mother-of-pearl was cut up in the process of manufacture.
From the appearance of the stria? when they are divided lengthwise, pear-shaped pearls appear to have been spherical at one time. During a stage in the growth, the forming layer has curved away from the centre at one section of the sphere to a point. Succeeding layers, following the innovation, are deposited around the extension until it becomes suffi-ii                                  161
Ch. 8: Genesis of the Pearl Page of 358 Ch. 8: Genesis of the Pearl
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page