54 
is much larger than that stated, as is apparent from the diagram. 
The growth of the crab which completed its second year in the 
Waddington series was plainly retarded by confinement. It is more 
than likely that a crab of 1 inch at the end of its first year would be 
about 2^ inches at the end of the second year. Such a crab would 
reach a size of about Sf inches at the end of the third year. At this 
period the cuticle is evidently not cast until the autumn of the next 
year as is apparent from the following example which is also shown 
on Chart VIII. A female measuring 3A inches was obtained at the 
end of May, 1908, and was kept in the laboratory until the ecdysis 
which took place during the night, July 29-30. Early in November 
this crab, which then measured 3If inches, was transferred to the 
tank on the rocks where she was found to have cast about 
August 1st this year. Unfortunately, through a slight acci- 
dent to the framework of the tank, she effected her escape 
and the size . gained after the last ecdysis was not deter- 
mined, but she appeared to be about 4f inches. The ecdysis 
at the end of the fourth year thus brings the crab we are 
considering to a size of about 4f inches. It is also very probable 
that sooner or later, after the lapse of another year, another ecdysis 
will occur, the size now being about 5f inches. As regards this 
period of the life of a crab it has to be recalled that the gradual 
diminution in the rate of growth renders it unlikely that the size 
will be altered at the end of the next year. I have had before to record 
examples of crabs which certainly could not have cast every year. 
One of these {vide Report for 1898) was a female measuring 
inches. This crab cast on August 12th, attaining a size of 
6f inches. She was hard in December and was retained until June 
when she died. This crab would more than likely have come into 
berry at the end of that year and would not have cast therefore 
until the lapse of two years. There is now in the rock tank a crab 
got from Beadnell on November 5th, 1903, measuring 6 t% inches. 
She was hard but she did not come into spawn until end of 
December, 1904. It is evident that this crab will not cast until the 
autumn of 1905. This is a period of three years since the last 
ecdysis. The female also shown in Chart VIII., measuring 
originally 5H inches, and which cast on September 17- 18th, 1903, 
and then reaching the size of 6 ^ 9 ^ inches, has not cast at all in 1904.'‘' 
The same conditions, it may be remarked, hold good with regard 
to the lobster (vide Rep., 1901, p. 48.) 
*See also Williamsoii, 22ud Rep. S. F. B., p. 13C, 1904. 
