64 
Sexual differentiation appears to take place perhaps at the end 
of the first year in the case of the first hatched, but with all at the 
end of the second year ( April). This gives an advantage in weight 
to the males, but the berried females attain a greater weight for the 
same size. 
After the age of four years I have not attempted to express the 
growth. It is more than likely that the limits in variation will he 
narrowed after that period, if not before, by the crabs in succession 
making their last moult — absolutely the greatest — and, sooner or 
later, growth in weight will cease likewise. The females will take 
longer to attain their final size than the males. For example, suppose 
a female measuring 42 mm. is impregnated, and comes into 
“berry” in December, she will still be in “berry” say in April, 
and still measure 42 nuns. She will cast again, very likely once, 
and be impregnated a second time. She will now measure say- 
52 mms., and this will be her size for another year, perhaps two 
years. At the next casting she will measure say 65 mms , and 
is now 5 or 6 years old. We are justified in supposing, therefore, 
that the females may live to 7 or 8 years before they reach their 
limit in growth, and two or three years more after that has taken 
place. 
The concluding portion of this paper with reference to the 
growth of the edible crab is withheld at present. 
