150 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



not be fed otherwise, attended to the reception and transfer of fresh collections, and 

 made himself generally serviceable within and without the aquarium. 



I have neither time nor inclination to enter into a systematic history of our oper- 

 ations during the season, but will only select from the items of our experience some of 

 those which seem tome the most interesting or the most profitable for future guidance. 



First, with reference to the planning and arrangement of the aquaria. Impressive 

 and pleasing as is the general effect of the circular disposition of our tanks, I would 

 not now plan a circular building like ours for an aquarium in which great crowds of 

 visitors were to be received. Something is lost in the fact that few of the aquaria can 

 be seen at once, but the lack of sufficient provision for a free movement of the air 

 through the corridors is a much greater defect. The two double doored entrances were 

 distant from each other only a little over a fourth of the circumference of the building, 

 and the radiating passages leading inward from them cut the circnlar corridors between 

 the rows of tanks into two very unequal segments, one approximately 75 feet long and 

 the other 190 feet. In this longer passageway the air was practically stagnant much 

 of the time, and often so offensive with the emanations of the crowd that sensitive 

 persons could not stay in it. A rectangular building with opposite entrances at ends 

 and sides would have permitted a much freer movement of both air and people. Still 

 better, perhaps, would have been a structure in the form of a Greek cross, with a low 

 central dome and entrances at the ends of the arms. 



My summer's experience fully convinces me that in the large fresh-water aquarium 

 the deep glass-fronted tank should be in great measure replaced by shallow basins or 

 pools or basin-like tanks borne on raised foundations, or with sunken walks between, 

 and left freely open above to both air and light. These basins should not be set so 

 low as to give a distorted view of the fish when looked down upon from above, nor so 

 high that a person of average height might not readily see to the bottom while stand- 

 ing a little distance away. If the bottom were saucer-shaped, with shallow water at 

 the edges, minnows and larger fish might well be kept together with charming effect, 

 and suitable plant decorations could be introduced without obscuring unduly the view 

 of the interior. Among my reasons for a preference of the open pool is the advantage 

 thus gained in the inevitable struggle with parasitic fungi infesting fresh-water fish. 

 As the salt-water species are free from this difficulty, there is no objection, so far as 

 they are concerned, to the closed tank now in general use. It is clearly a great error,] 

 however, to plan any large aquarium without provision for small open tanks in which 

 the smaller animal forms may be shown to good advantage, and especially those which 

 may best be seen from above. This is as true of fresh-water animals as of ocean forms. 

 Many of the oddest and most interesting aquatic creatures are too small to be commonly 

 noticed, even if extremely abundant; but are large enough, nevertheless, to arouse 

 great interest and repay careful observation if put in small, readily accessible tanks. 



The comparative advantages of the open-pool system were continuously illustrated 

 throughout the season by the history of our collections in the large central pool. 

 Id this basin, L'i feet deep, with a surface area of 530 square feet and a bottom of white 

 sand, trouble with fungous disease was at all times practically insignificant; while iu 

 the deep, narrow tanks adjacent constant and often unmanageable difficulty was experi- 

 enced. This contrast is the more remarkable if we consider that the central pool was 

 used as a receiving tank, and consequently often contained many specimens injured 

 in transit. The shallow basin was also much more easily kept clean. 



