100 The Pearl Oyster of Ceylon, [no. 5, new series, 



ova, their form preserved, although saturated with arrack. Under 

 the microscope the ovum is seen to be pear-shaped ; each measured 

 3-1000 part of an inch in diameter, at its broadest part ; longitudi- 

 nally it is 6-1000 with a short pedicle attached. I have calculated, 

 with the micrometer, the number of eggs contained in the ovariaof 

 an Oyster of five or six years of age, and I find that there cannot 

 be less than twelve millions. Leuwenhoeck states, that ten million 

 eggs exist in one European edible Oyster. If we consider how 

 few of these millions cf eggs can arrive at the mature condition of 

 „ a living Oyster, and the great demand that man makes upon the 

 species for his gratification ; we can only see in this great fact, the 

 bountiful provision made by the Creator for a wise and beneficial 

 purpose. 



In concluding this first Report, I shall briefly recapitulate 

 the important discoveries I have already made. 



(a) The Pearl Oyster is more tenacious of life, than any bi- 

 valve Mollusc I am acquainted with. It can live even in brackish 

 water, and in places so shallow, that it must be exposed for three 

 or four hours daily to the sun, and other atmospheric influences. 



(b) That it has locomotive powers, beyond any idea which can 

 be formed from former observations. 



(c) That the power of moving from place to place, is inhe- 

 rent, and absolutely necessary, in early life, for the due perform- 

 ance of the animal functions. This is obvious from the fact, that 

 if a cluster of young Oysters stayed permanently in one place, ad- 

 hering to each other, the growth of the animal, and particularly of 

 the shell, would be prevented. 



(d) That the Pearl Oyster will move about in search of food, 

 if the locality, in which it is originally placed, is not rich in its na- 

 tural supplies. 



(e) That it will move from its original situation, if the water 

 becomes impure, either from the decomposition of vegetable or 

 animal matter, or muddy ; and, probably too, if there is a large in- 

 flux of fresh water. 



(f) That if the water is agitated to an inordinate degree, the 

 Oyster will leave its old mooring place and seek another. 



