THE PEARL FISHERY OF 1904. 



23 



Modragam the young already noted were found well grown and nourishing, and, while 

 their actual age was only I } to 1^ years, many, especially upon the Modragams and 

 South 'Cheval, had the appearance of heing 2 years old. On the Muttuvaratu and 

 Dutch Modragam the older oysters had made no increase in size, and were in an 

 unhealthy and miserable condition. Mixed with them were considerable numbers of 

 a younger generation, apparently over 1 year old. This year, as already stated, the 

 older generation proved to have died off upon the Karativo, while the younger 

 generation found last year had made fair progress and appeared moderately healthy. 

 Similar conditions, I believe, characterise the Muttuvaratu this year, judging from 

 the rather meagre data at my command." 



Rate of Increase in Size. So little is known with exactitude concerning the rate of 

 growth of oysters, that the following tabulation by Mr. Hornell of the observed 

 increase in size of these younger oysters has considerable value. 



Table showing Rate of Growth of Oysters aged 2\ to 2| Years, March, 1904. 



Date. 



Age in years. 



Size in millimetres. 



I. South-east and South-central Cheval :- 



AtoJL 



March, 1902 . 

 November, 1902 

 March, 1903 . 

 1904 . 



II. MODRARAM PAARS: 



March, 1902 



1903 (North) . . . 



1904 (South) . . . 



III. North-west Cheval : 



March, 1902 



November, 1902 



March, 1904 



1904 (another locality) 



li 1_2_ 



IS 'l2 

 l 1 l- 1 



2 1 .. 2 J 



12 12 

 l 1 - li 



2i 2 



I 2 " T2" 



ii 1 - 



12 '12 



01 91 



9. 1 9 1 



35-00 x 32 00 x 

 50-57 x 47 -52 x 

 54-41 x 49-75x20-38 

 67-12x61-16x27-24 



37l5x 33-20 x 



6117x54-50x24-28 

 68-68x64-16x27-28 



33-50 x 30-75 x 

 47-64 x 44-36 x 

 56 -60x52 -60x24 -56 

 61-33x57-40x23-70 



When these records are extended over the remaining life-period of these oysters 

 we shall have, for the first time, reliable data as to the relative rate of growth from 

 year to year upon three of the most important of our oyster banks. 



