488 MR. F. BALFOUR BROWNE ON FRESH-WATER FISHES. 
For some time 1 fed them almost entirely upon Perch larvae, 
of which I had a large supply, and they seemed to thrive very 
well on them. Pike of 25 and 30 mm. had no difficulty in 
disposing of larvae of 10 and 15 mm., and, from the way their 
own numbers thinned down, I fancy that they must have 
successfully despatched their own smaller brethren although, 
strange to say, I never saw them attack one another. 
There are other species of fish, such as the Rudd, and Tench 
which inhabit the Broads, the early stages in the life-histories 
of which have not, so far as I am aware, been investigated. 
I believe that there is enough to be done in watching the 
development of any single species to occupy a Naturalist for 
a whole season. What I have described in the present paper 
are merely a few facts observed during the course of other 
work, and I hope that they may serve to direct the attention 
of others to the life histories of our fresh-water species. 
DESCRIPTION OF PLATES. 
Plate I. — 
1. Egg of Perea Jluviatilis , the Perch. 
2. Egg of Acerina cernna, the Ruffe or Pope. 
3. Egg of Esox Indus, the Pike. 
4. Newly hatched larva of Perea jluviatilis. 
5, 6. Esox Indus, newly hatched and 9 days old. 
Plate II. — 
1. Egg of Abramis brama, the Bream. 
2. Egg of Leudscus rulilus, the Roach. 
3. Newly hatched larva of Abramis brama. 
4. Larva of Leudscus rulilus several days old. 
5, 6. Egg and newly hatched larva of Gasterosteus pungetius, 
the nine-spined Stickleback. 
