406 FISH CULTURAL ASSOCIATION. 
Mr. BLackrorp : We have found spawn in eels since Octo- 
ber, always more or less developed. About the rst of December 
last Mr. Fred. Mather measured the eggs of a six-pound eel, 
and estimated their numbers at nine millions. That eel was 
caught at Gravesend, Long Island. The eel shown here to-day 
came from Cape Vincent, near the head of the St. Lawrence 
river. I think it highly probable that the male eels are small, 
and that if Mr. Roosevelt had all the facilities which Fulton 
Market affords, he would most likely have found them. 
Mr. FREDERICK MATHER read the following paper on the 
Management of Public Aquaria, with a plan for reducing their 
running expenses : 
In the practical working of a large public aquarium it is 
found that the well-known principle upon which parlor-aquaria 
are kept, known as the “self-sustaining” principle of organiza- 
tion by means of plant-life, is deficient in furnishing a sufficient 
quantity of oxygen to completely consume all the feculent 
matter, and to sustain the large specimens and numbers of ani- 
mals required to be shown. Another reason is that there are 
some forms of life which refuse to live in still-water, no matter 
how well it may be supplied with oxygen. In fresh water this 
is seen in the salmon family, some of the percoids and brook- 
cyprinoids, while in a self-sustaining marine aquarium there 
are but few fishes that will live. . 
Two modes then remain as at all possible for an aquarium 
built upon a large scale, viz.: The introduction of air by means 
of an air-pump, and the circulating system. The former of 
these methods is only fit for a temporary exhibition, and even 
then requires great care and cleanliness or the fish will not 
thrive even for a few days ; and inthis I found my views cor- 
roborated by the experience of the oldest and best aquarium- 
keepers in Europe, most of whom have entirely abandoned the 
use of air-pumps as the cause of more harm than good. The 
great Brighton Aquarium has a combination of methods, the 
sea-water being pumped from the sea into reservoirs and then 
distributed ; at the same time a system of air-pipes is relied on 
for zration as the water is kept until it gets cloudy, and then 
eee — eee Eee 
