LECTURE XI. 



cretions have been formed *. Besides those found 

 -in the body of the animal, several are often observ- 

 ed rising from the internal surface of the shell, to 

 which they are closely attached, so as not to be 

 completely round, and are therefore considered as 

 of little value. The largest Pearl-Shells, and such 

 as are most encrusted with extraneous marine sub- 

 stances, as Serpula?, Corals, &c. are in general ob- 

 served to be most productive of pearls ; while the 

 smaller and smoother shells afford but few, or so 

 small as to be of no importance in commerce. 



In addition to what has been said relative to 

 Pearls, we may add, that irregular or grape-shaped 

 pearls sometimes occur, which seem to be owing 

 to a coalescence of several smaller ones into one 

 mass. One of the noblest pearls on record is that 

 which Cleopatra is absurdly said to have dissolved 

 in vinegar, during an entertainment which she 

 gave to Mark Antony, and afterwards to have 

 drank it. We must surely suppose that she 

 caused it to be well bruised first, before she put it 

 into the vinegar. It was a pearl belonging to a 



* According to Cuvier pearls may be considered as formed by 

 an extravasation of the calcarious matter with which the animal 

 AS furnished, for the augmentation of its shell. 



