5b 
ON THE GROWTH OF THE CRAB. 
By A. MEEK, M.Sc. 
The great length of the spawning, and, consequently, also of the 
hatching season in the case of fishes and of the higher Crustacea, 
makes it very difficult to state definitely the relation of size to 
age. The period is often one of several months, and thus the first 
hatched of one season reach a size in one year which is only 
attained in two years or more by the later hatched. At the 
limits of variation, therefore, for a given age, it is not merely 
difficult, but indeed impossible in most cases to say to which of 
two years the specimens belong. This overlapping of the 
successive generations is shown by the fact that in a very short 
time, usually less than a year, examples of a species may be 
obtained of all sizes, from the smallest to the largest. It is 
thus difficult and often uncertain attempting to read the facts 
of growth from an analysis of such measurements. The records 
of growth, then, in the case of individuals kept over long periods 
are therefore of the greatest importance, and render the task 
easier and the results more definite. In the present case, I am 
fortunately in the position to approach the subject by first 
bringing under review certain details with relation to the growth 
of the Common Shore Crab, Green Crab, or Dog Crab, 
C-AHCINUS MCE NAS. 
They refer to the excellent series illustrating the growth of 
this species presented to the British Museum of Natural History, 
London, by II. T. Waddington, Esq. For the measurements and 
the dates I have to thank Dr. W. G. Kidewood. To the table 
I have only added columns showing the number of days intervening 
between each successive ecdysis (casting of the shell! and the gain 
made at each period. (I take it that the first date refers to the 
capture, and thus the first interval of days in each case must be 
neglected.) I have also expressed the measurements in graphic 
form in Chart VIII. 
The shore crabs which were kept under observation by 
Capt. C. Du Cane* were got with ova at the end of December. 
The embryos began to hatch in the beginning of March, but it was 
only towards the end of April that they hatched in abundance. 
1830, Ann. and Mag. Nat. lli*t. vol. III., imge 138. 
