104 American Fisheries Society. 



This method of aeration permits the carrying of fish in very 

 shallow water in a comparatively quiet state, since the water in the 

 fish compartment is not disturbed by violent waves having behind 

 them the inertia of the entire volume of water in the vessel. The 

 artificial water level produced by agitation, either manually or by 

 the motion of the vehicle, creates a gentle current through the 

 bottom apertures of the tray which carries all excrement to the 

 bottom of the outside receptacle, where it remains on account of 

 the comparative stillness of the water at that point. 



When the container is stationary the water within the lower 

 tray returns to its normal level, to be determined by the character 

 of the fish to be shipped. When shipping large fish as distinguished 

 from fry the water should be of sufficient depth to permit the fish 

 to swim about with their dorsal fins slightly exposed. 



When the supply of oxygen in the water becomes depleted the 

 fish begin to feel discomfort, which manifests itself in increased 

 activity and results in the splashing of the water because of its 

 extreme shallowness. 



The functions of the upper tray are as follows : 



1. To act as a cover and baffle plate whenever the motion is sufficient 

 to cause the water to splash against it. The perforations are of such dimen- 

 sions that the water cannot pass through in sufficient volume to slop over 

 but will percolate back into the tray, becoming aerated by the process. 



2. The upper tray also serves as a receptacle for carrying ice when cold 

 water fishes are handled during the warm summer months. The perforations 

 permit the ice water to drip into the bottom tray, carrying with it a large 

 supply of oxygen. Under such conditions the outer flap of the absorbent 

 jacket is drawn over the ice and retained in position by a drawstring. 



SIPHON. 



I'he object of the siphon is primarily to remove sediment and 

 pollution from the pail and secondarily to provide means for main- 

 taining the water level at a substantially fixed point, and inci- 

 dentally to moisten the canvas jacket. These results are accom- 

 plished by combining with the pail a siphon so arranged that 

 by tilting the pail, or by addition of water to the containar, 

 by the melting of ice or otherwise, the siphon may be submerged 

 and caused to operate to remove sediment and polluting matter and 

 to reduce the water level to a predetermined quantity. 



The siphon may be caused to function regardless of the water 

 level, whenever it is desired to remove polluting matter, by simply 



