53 

 Weight of Pearl Oyster Shells. 











Weight 



Increase in 



Locality. 



Date. 



Age. 



1 



Number 

 weighed. 



per 100 

 pairs of 

 values. 



weight in 



year 

 preceding. 







YEAS. 



PAIRS. 



OUNCES. 



OUNCES. 



f 





4 



10 



1-00 



, . 







l£ 



10 



3-75 







March 18S5 



if 



10 



6-25 



5-25 







2i 



10 



700 



3-25 





April 18S6 



2* 



to 



7-50 



1-25 







31 



10 



8-50 



1-50 







31 



10 



10-75 



3-25 





October 1S87 



41 



10 



13-00 



4-50 





November 18S8 



54 



10 



15-25 



2-25 







H 



10 



16-62 



. . 



I 



„ „ 1890 



6f 



3 



17-64 



1-02 



Westem Cheva] Par * f 





S, 



13 



2-50 





(Tvpe in^eriEEdiate between, 1 





If 



13 



7-50 



5-00 



She f reelv grown oysters of | 



1873 



2£ 



60 



11-88 



4-33 



the South and South-East ^ 













Cheval and the extremely 1 



November 1?73 ., 



**i 



100 



12-81 



. . 



stunted ones from the Mut- I 



(fished) March 1874 



9» 



45 



15-31 



4-43 



tuvaratu). L 



.. 1S75 



a 



47 



1S-75 



3-44 



f 



March 1874 



s 



33 



2-25 





Sonth-East Cheval Par * . . 1 



1S75 



it 



60 



8-50 



6-25 



(Free growth tvpe) .. .. 1 





■)3. 



150 



13-44 



3-94 



I 



„ 1S77 



H 



51 



18-75 



5-31 



* In Captain Dcnnan's table the ages of these are given as three months older than shown here; the figures now 

 given, I believe, approximate more closely to the actual ages. 



Analysing the above table we obtain the following comparisons : — 



Tolayiram Par. 



Weight at f year 



If years 



JJ 



2-3. 



03 



JJ 



JJ 



°i 



JJ 



}> 



44 



jj 



JJ 



5{ 



jj 



eight 



at f 



year 



>> 



If 



years 



jj 



Q3 



jj 



jj 



u 4 



3) 



jj 



n 



JJ 



eight 



at f 



year 



JJ 



If 

 24 



years 



h 



- 4 

 03 



;> 



» 



u 4 



j> 



jj 



A3. 

 H 4 



jj 



North- West Cheval Pat. 



South-West Cheval Par. 



oz. 



1-00 



6-25 



7-50 



10-75 



1300 



16-62 



2-50 



7-50 



11-88 



15-31 



18-75 



2-25 



8-50 



13-44 



18-75 



The weight of three typical oysters from the fishery held on the Muttuvaratu 



Par in 1891 is 5 375 ounces, equivalent to a 



eight 



of 17-916 ounces per 10 pairs 



of shells when the oysters were approximately Q~ years old. 



The annual increase in weight of oysters on the Tolayiram Par compares, as will 

 be seen from the above, very unfavourably with the comparatively stunted oysters 

 characteristic of the Western Cheval. The nearest approximation was at the age of 

 If year, when 10 Tolayiram Par oysters weighing 6£ ounces were but 1J- ounce less 

 than the weight of a similar number from the North-Western Cheval. During the 

 next twelve months, however, the latter gained i\ ounces as against an increase of 



14 



