Msm 



Fis 12 Figures showing the development of the Pearl Sac 

 according to Kubbel (modified from Eubbel). Per., periostracum-like 

 substance forming the nucleus of the pearl. Epi., epithelium of 

 mantle. Pe. Sac, pearl sac. Pe., pearl. Conn., connective tissue 

 of mantle. 



8 



