The Reproductive Power of Eels. gl 
were semi-transparent, evidently just hatched, and came from 
the pond. They grew rapidly when not killed, and some 
escaped our notice. During my temporary absence I was in- 
formed that they were eating the trout-fry, and although I 
returned on April 17th, many of the latter had been de- 
voured. In moving the rest, I had to dig up the sand, and 
found it filled up with eels from two inches to six inches 
long, which had buried themselves in it, and were hidden 
away wholly out of sight. There were three screens of fine 
wire-netting in the trough—one at the head, one at the foot, 
and one between the two. Now that the sand was gone, 
the young eels were to be seen in myriads passing from the 
main pond down the trough, and thence into the first pre- 
serve. The salmon had grown so large that they would oc- 
casionally eat one, and in the lower pond were now the 
large trout and few or no eels. 
It was impossible that the eels could have come up 
stream from the salt-water bay, as the discharge from the 
lower preserve was through a pipe, also grated, which had 
a fall of two feet perpendicular clear of the bank. Besides, 
we saw them descending the trough in black masses, and 
while doing so they endeavored to get through the lower 
screen, never seeking to pass the upper one. By April 26th, 
as they collected at the lower screen, they were taken out by 
millions in a small net, made for the purpose of mosquito- 
netting. Most of them were so young that the heart could 
be plainly seen, and its pulsations, which were rapid, noted 
under a microscope. I could find nothing of the supposi- 
tious heart in the tail, and I decidedly doubt its existence ; 
but my magnifying-glass may not have had sufficient power. 
In a few days after their first appearance the young eels 
would lose their translucent color and became black and 
