The Age and Growth of some Eels from a Worcestershire Pond. 23 
A table of the average lengths of the different age groups would 
show the growth of these eels more or less accurately if each group 
had about the same number of eels, and better still if for both 
sexes. Unfortunately, this was not possible, and therefore the 
results are more or less accurate according to the number in each 
group. Take, for instance, the males. I caught 2 belonging to 
group VII, 13 to VIII, 13 to IX, and 1 each to X and XI. It is 
quite obvious that one can compare averages taken from equal 
numbers more accurately than from 12 and 2. This also applies to 
the females ; and for this reason I give below the average lengths 
in this table, the number of eels in each age group, as also the 
differences I observed between the number of zones of the scales 
and the otoliths. 
In all I examined 78 eels (30 males, 46 females, and 2 of 
undeterminable sex), and I add here that all these 76 eels had 
perfectly well-developed sexual organs leaving no possible doubt as 
to their sex. 
The zones on the otoliths were counted several times, and the 
grinding down was carried out with the greatest possible care. 
Males. 
Group 
VII 
VIII 
IX 
X 
XI 
Length in cm. 
31 
30-30 
31-69 
36 
40 
Number of eels 
2 
14 
12 
1 
1 
D 
4 
4-6 
5-6 
5 
6 
All the males were yellow eels except the one belonging to 
group XI, which was nearly silver ; the eyes were enlarged, the 
dorsal side and pectoral fins were nearly black, but the ventral 
side was slightly grey ; the sides showed bronze metallic reflections, 
and the flesh was quite firm. 
Females. 
Group 
VII 
VIII 
IX 
X 
XI 
XII 
XIII 
XIV 
XV 
Length in cm. . . 
33-5 
34-57 
34-41 
40-5 
41-35 
44 
44-5 
48 
48 
Number of eels 
4 
7 
13 
4 
7 
5 
4 
1 
1 
D 
4 
4-5 
5-6 
5-7 
6-8 
7-9 
8-9 
10 
10 
All the females were yellow eels, although in some of the 
larger ones the ovaries were beginning to be opaque like those of 
silver females. 
