PLATE XL 
The thrce-spineJ Stickleback is a very common species in many of 
our rivers, as in those of Europe in general; and, as Mr, Pennant 
writes of those in the fens of Lincolnshire, sometimes appear in tlie 
rivers on the continent in such amazing quantities that they become 
a perfect nuisance, and are taken to manure the lands. “ 
Spalding,” says the author, “ there arc once in seven or eight years, 
amazing shoals that appear In the Welland, and come up the river m 
the form of a vast column. They are supposed to be the multitudes that 
have been washed out of the fens by the floods of se\‘eral years, and 
collected in some deep hole, till overcharged with numbers, they ate 
periodically obliged to attempt a change of place. The quantity is 
so great, that they are used to manure the lands, and trials have been 
made to get oil from them ; a notion may be had of this vast shoal, 
by saying that a man employed by the farmer to take them has go* 
for a considerable time four shillings a day by selling them at a half- 
penny per bushel.” Gineliii says they are also used to fatten ducks 
and pigs, and otliers observe that they are taken in great quantitis® 
about Dantzig, by people who press an oil from them. 
This fish is certainly not entirely peculiar to fresh water, for 
have known it taken at a great distance out at sea in the Sprat and 
Herring fisheries : such however we observed differed a little i*^ 
colour, being of a greener and morC silverly cast than those found in 
the fresh watei's-, but they are undoubtedly in no respect specifically 
different from them. The colours of those In fresh water also vary 
at certain seasons, and it cannot have escaped remark, that when the 
female is in full roe, the chin and breast assumes a lovely red colour- 
T he length of this species rarely exceeds two inches ; in this coun- 
try, it is usually when full grown about an inch and an half, or at 
