8 
NATURE NOTES 
tiny black thing as long as one’s little finger nail, and, when not 
lengthened out, hardly larger than the head of a good sized pin. 
These wretches were ubiquitous, and their numbers astonishing. 
The bottom of the water was alive with them, and, in spite of 
all my filtering, on one occasion they found their way into my 
boxes, and destroyed a thousand freshly hatched fry. By way 
of experiment I placed six of these leeches in a saucer with 
three of the fry a few days old, and also an equal number of 
unhatched ova. In an incredibly short time the skins of the fry 
alone were left, while the outer membrane of the ova proved too 
tough for their attacks. When the umbilical sac had been 
absorbed, the boxes soon became too small for my baby fish ; so 
I made a tiny pond for them at the side of the waterfall, taking 
elaborate precautions against their escaping into the lower moat, 
where their lives would not have been worth a day’s purchase. 
No sooner were they installed in their new quarters than a fresh 
enemy came upon the scene. In the first few minutes several of 
the troutlets turned on their sides, and on carefully removing 
them I found a leech-like looking creature had fastened on their 
gills. It was no larger than the little black fellows I have 
already described, but was lighter in colour and with a large 
sucker at one end. When once attacked by these they always 
died. I have seen the same animal on the eyes and head of 
adult fish, but its name I do not know. Leeches, then, are 
among the most formidable foes to trout in early life. To these 
may be added a whole host of insects that are to be found in 
every piece of water the country through. The savage larva of 
dragon flies, and of most water beetles, devour anything and 
everything almost that comes in their way. Verily their name 
is legion. Need I name any more enemies, from that beautiful 
little shark, the stickleback, upwards ? No, it would take too 
much space ; and besides, the larger they are the better they 
are known, though the amount of destruction seems to be in 
inverse ratio to the actual size of the foe itself. 
I have witnessed some other curious and interesting sights 
connected with my troutery. I have been present at, and seen 
fought out, pitched battles between rival fish. They generally 
last half an hour or so, and are carried out with determination 
and ferocity on the surface of the water. It is easy to tell when 
one takes place, for the two fish slowly circle round each other, 
generally head to tail, a few feet apart. Their back fin is raised, 
and, with the tip of the tail, is out of the water. Then one 
suddenly dashes at the other and tries to seize him just above 
the tail. If he succeeds, he holds firmly on, shaking his enemy 
like a bulldog, and driving him broadside through the water. 
Short, thick fish generally gain the day, for they can turn more 
quickly than long and slender ones. What these fights were 
about I never could quite understand. They usually took place 
in the summer. Was it for some coveted spot, or do they settle 
who their wives are to be some time before the spawning season 
comes round ? 
