12 HULL SCIENTIFIC AND FIELD NATURALISTS’ CLUB. 
gudgeon afforded us considerable amusement. Its length was 
about five inches, and the gudgeon were not less than three 
inches long. One morning one of the latter had lost the number 
of its mess, for the perch had seized him, and was swimming 
about the tank with half-an-inch of the gudgeon’s tail protruding 
from its mouth. By evening the head having apparently 
digested some more of the victim had become engulphed, and in 
forty-eight hours (not before) the last vestige had disappeared 
down the little glutton’s throat. By the fourth day he was ready 
for another, and this process went on till the perch was the sole 
occupant of the tank. Perch are found in considerable numbers 
in Frodingham Beck, and in that reach of the Driffield Canal 
between Frodingham Beck and West Beck end, and are found in 
greater or smaller numbers all over the river. The average 
weight is perhaps five or six ounces, but fish of much larger 
weight are often caught. Two stuffed specimens, before me as I 
write, one caught at Top Lock, and the other at Leven Canal 
end, weigh two pounds nine ounces and two pounds five ounces 
respectively. No larger ones from the river have come under my 
notice. 
Tue MILLer’s THuMB.—This oddly shaped fish passes its 
life securely hidden away under a stone, or other convenient place 
of refuge. I believe it makes a hollow under the stone for itself 
to swim into, and waits with its head near the opening, watching 
for some unsuspecting fresh-water shrimp, or other of the smaller 
denizens of the stream which may pass by. It is not at all 
particular as to its diet ; even the stickleback, with its formidable 
spine, not being safe from its cavernous jaws. On one 
occasion some sticklebacks which we were carrying in a can 
showed signs of exhaustion, and to relieve the rest the ones which 
seemed likely to succumb were taken out and thrown into the 
stream. One happened to be washed past the retreat of a miller’s 
thumb, which at once rushed out, seized the unoffending stickle- 
back in its mouth, and took it under its place of concealment. 
We waited a short time, and then looked under the stone to see 
if it really had devoured its prey. This it had done, spine and 
all! The miller’s thumb spawns under a stone—the roe, in 
general appearance, not looking unlike that of the salmon. The 
ova cohere firmly together, and the whole mass adheres to the stone. 
It may be found in April by turning over the stones which are 
known to be the haunts of the fish. It occurs in all the small becks 
which feed the Hull, especially where large chalkstones abound in 
the bed of the stream. 
STICKLEBACKS are found occasionally in the open river, but in 
my opinion are there from necessity, and not from choice. They 
