53 
the afternoon of September 7th. This young lobster measured 
20*5 mm. (fi-inch). It may be said to be about 2 months old. 
Another specimen in my possession was obtained on March 20th, 
1900, at Cullercoats— a male, measuring 76 mm. (3 inches). This 
one might be 8 to 9 months or a year later in age. At this rate it 
will be about 4 or 5 years before maturity is reached. The 
American lobster comes to maturity at about 9 to 10 inches, and 
Fullarton came to the same results. On our coast the females are 
usually 10 inches and over, when in the berried condition, but I have 
had examples measuring 9J and 9f inches. 
(B ). — Crab. — Two years ago with the aid of three of the excellent 
series of stages prepared by H. J. Waddington, Esq., Bournemouth, 
I published a paper on the Growth of the Shore Crab'^ I intended to 
print at the same time the conclusions I had arrived at with regard 
to the growth of the edible crab, but, feeling that my facts were 
all too inadequate, I withheld the latter portion of the paper in 
the hope that^ I would be able to obtain more information on the 
subject. 
With the aid of a grant from the Eoyal Society I had made a 
strong iron tank which was placed in the concrete receptacle already 
available on the rocks near spring tide low water mark, and 
hatching boxes and a large observational tank for the laboratory. 
I have not to remind those interested in the laboratory that the 
latter, with the experiments then in progress, was destroyed by fire 
last Easter. In the meantime Williamson'''* has published a paper on 
the subject based again on series of the edible crab furnished by Mr. 
Waddington, and now I think it advisable to state to what extent 
my enquiry reached when it was brought to an end by the fire. 
On the accompanying chart (Chart VIII.) the thick lines mark 
the ecdyses which took place at Cullercoats. I have ventured to 
introduce into the chart the three series of stages from Mr. 
Waddington’s experiments detailed by Williamson. These are 
distinguished by the interrupted lines in the lower part of the chart. 
The year of the crab’s life is supposed to begin on the 1st August. 
It is quite clear from the chart that the small crabs which appear on 
the rocks about April, increasing in numbers up to July and August, 
and disappearing again about the latter end of September, are crabs 
beginning their second year and include some beginning their third 
year. In other words the small crabs of 1 inch to inches whose 
ecdyses are shown may be said to be 1 year old. But the variation 
* Rep. XortM. Sea Fish Com., 1902. 22nd Rep. Pish Bd. for Scot., 1904. 
