148 



TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 





of the beasts from their shells takes time, and evaporation is 

 constantly going on. The basin and its contents are then 

 placed in an electric oven at 105° C. and dried until a constant 

 weight is obtained. It is probable that all the water is not 

 removed by this method, since the mussels become covered 

 with a hard, impermeable skin. 



From the differences of wet and dry weights the amount 

 of water in the tissue is obtained. The dried mussels are 

 powdered in a mortar and stored in small bottles. It is from 

 this powder that the percentages of fat and protein are cal- 

 culated, two or three samples being run through together. 



The following example is given to show the method of 

 tabulating the observations : — 



October 29th, 1920. 



Sample of 19 mussels taken from the Little Out Skear, close to 

 the Gunnel through into Heysham Lake. 









Weight 



Weight 



No. 



Length. 



Total weight with shell. 



of 

 shell. 



of 

 flesh. 





cm. 



grammes. 



grammes. 



grammes. 



1 



6-55 



20-300 



10-790 



9-510 



2 



6-00 



15-997 



9-206 



6-791 



3 



6-80 



18-598 



9-821 



8-777 



4 



5-95 



16-721 



8-557 



8-164 



5 



6-15 



15-044 



7-746 



7-298 



6 



6-80 Av. 6-375 



19035 



10-487 



8-548 



7 



6-20 



Totals 105-695 



56-607 



49-088 



8 



6-30 



Averages 17-616 



9-435 



8-181 



9 

 10 



6-55 



6-80 















11 



6-25 









12 



6-15 









13 



6-40 



Weight 7-19 ... 245-04 



124-575 



120-465 



14 



6-95 









15 



6-35 



Average 18-850 



9-580 



9-270 



16 



6-70 









17 



5-95 



Difference in averages 1-234 



0-145 



1-089 



18 



5-90 









19 



6-25 Av. 6-365 









The difference in the averages of 1-G and 7 to 19 in this case 

 are extreme when compared with most of the other samples. 



