The Age and Growth of some Eels from a Worcestershire Pond. 25 
I think that the exceedingly slow growth of these eels can be 
put down to the unfavourable conditions prevailing in this pond. 
There is a great difference in the growth of the two sexes ; the 
males remain much smaller than the females. 
The largest male known only measured 51 cm., but females 
can grow up to 1*50 metre, and I myself have seen females over a 
metre long. 
The males rarely measure more than 48 cm., and it is quite 
common to find silver males in localities near the sea measuring 
from 33-40 cm. 
The smallest silver males measure 29 cm., but one does not 
often find silver females measuring less than 45 cm. Naturally 
the males became silvered before the females ; one can find silver 
males belonging to group 1Y, but more often to groups Y, YI, 
YII, and YIII. The females take at least two years longer than 
the males of the various localities where I have collected eels. 
Personally, I have not seen a silver female younger than 
group YII, but probably under very favourable conditions they 
may mature earlier. The age of silver females varies greatly, and 
I have seen otoliths having certainly 15 dark zones. Their size 
also varies greatly ; one can obtain specimens 45-50 cm. long 
perfectly silvered, and one can find large yellow females of over 
80 cm. 
The males do not migrate so far from the sea as the females, 
and for this reason if one examines a quantity of small eels caught 
in a lagoon, estuary, etc., of, say, from 30-40 cm. long, the great 
majority will be males. 
I have not caught enough roach to be able to say much about 
their growth, but the perch, which are easily caught, are mostly 
very small, usually from 15-20 cm. or from 6-8 inches long ; I 
only once caught one of 8 ozs. 
As I only examined one nearly silver male I cannot say at 
what age they become silver eels ; but judging from the growth 1 
should not expect the males to do so before reaching groups YIII 
and IX, but perhaps some might with YII. 
The females would probably take at least two years more. 
Under favourable conditions the males might become silvered with 
groups IY and Y, but the age of the silver eels varies greatly. 
As I said before, this paper has no pretentions to be a study 
of the growth of the eels in this pond, but to show that under 
unfavourable conditions the eel can grow very slowly indeed. 
Unfortunately I did not examine a sufficient number of eels to 
obtain accurate averages for the different age groups. It would 
have been preferable to have examined eels caught during the 
winter months when growth is slow, but circumstances prevented 
this. 
The eel is commonly supposed to be a fast-growing fish, and 
