of the Fishery Board for Scotland. 333 
The herrings numbered 1155, of which 514 were females and 641 
were males. Most of them were spawning, but 40 females and 43 
males were spent. ‘The herrings as a whole were smaller than those got 
in February. Whether this was due to any extent to their having been 
soaking in weak formaline solution is doubtful; my experience with 
other fishes is that they do not appreciably diminish in length under 
such circumstances. The fact that they were measured by another 
person has to be kept in view, but, making all due allowances, I think 
it may be assumed that these herrings were on the whole smaller than 
those in the previous month. 
The table of measurements and the curve (Plate XIX.) show that the 
bulk of the herrings was composed of two annual series, but it is not 
very clear where the division occurs in this case. Theoretically, it 
should be about 24°5cm., and a consideration of. the curves and tables 
suggests that it should be placed at 244mm. ; but the division is some- 
what arbitrary. The separate curves for the sexes does not help much, 
except in the case of the males, where there are cusps or modes at 
23cm. and 25em., the depression being at 24cm. 
To this series belong 256 females and 319 males. Both have a similar 
range, from 211mm. to 244mm. (but the latter is no doubt greater, and 
possibly goes to over 25cm.); the modal size for each may be put at 
23-5cem. (9 inches); the means are 227-5mm. (or, if the series is 
extended to 254mm.—a centimetre more—it is 232°5mm.); the computed 
average sizes are, for females 252°8mm., and for the males 232:2mm. 
Combining both sexes, the group of 575 herrings have the same range 
as above, the same modes and means, and the avarage size is 232°5mm., 
or 9,5, inches. 
The second series of herrings begins about 245mm., or, if extended 
for lem. backwards, at 235mm. (97 inches). Where it ends is not so 
clear. The 2mm. grouping is as follows :— 
267 269 271 273 275 277 279 281 283 285 287 2899 991 
Gene leet 13), 12 5 4 5 g 
and the millimetre measurements are :— 
201 272 273 274 275 276 277 278 279 280 281 282 283 284 285 
8 8 4 2 3 2 2 L 1 1 1 - 1 - = 
It might end at 281mm., or 274mm., or at 277mm., and I take the latter 
(1032 inches). 
To this group belong 252 females and 317 males. Both have the 
same range, 245mm. (or 235mm.) to 277mm.; the modal size is about 
25em. (9{ inches) ; the means are 261mm. (or 256mm.); and the com- 
puted averages are, for the males 252°7mm. (almost 10 inches), and for 
the females 254:1mm. (10 inches). The group of 569 herrings has 
the same range, mode, and mean as described, and the computed average 
is 253'5mm. 
The difference between the first and the second series in the March 
herrings (on the averages) is, for females 21°3mm., for males 19-9mm., 
and for the series combined 21-Omm. 
There were other eleven herrings of larger size in the collection, viz., 
six females, measuring 28lmm., 283mm., 287mm., 288mm., 324mm., 
and 325mm.; and five males, measuring 278mm., 279mm., 280mm., 
287mm., and 304mm. 
These obviously belong to different annual series. It is very probable 
that the herring at 304mm. represents an older group than those smaller, 
while the two large females (12? inches) must be some years older, 
