BULLETIN OF THE UNITED STATES FISH COMMISSION. 183 



long time, in case it was desired to transport the ova long distances. 

 I tliink it would be found practicable to carry eggs on trays on damp 

 cloths for a period of 24 to 48 Lours without the least difficulty, pro- 

 vided a refrigerating apparatus was constructed in which the tempera- 

 ture could be kept at G0° to 6o^ F. ; below this temperature it would not 

 be safe to go, for the ordinary purposes of transportation from the 

 spawning grounds remote from the hatching stations. An important 

 matter to attend to in the application of the above plan will be to effect- 

 ively scald the cloths which are laid in the trays each time before they 

 are again used, or else they will become the nidus of untold myriads of 

 putrefactive germs which will lodge from in the air in dust, the reten- 

 tion and development of which would be favored by whatever of mucus^ 

 dead eggs, egg-membranes, and blood might adhere to the cloths from 

 one time to another. 



The putrefactive germs always liable to be conveyed in the impalpa- 

 ble dust constantly suspended in the air of houses in this latitude are 

 consequently much more insidious in their approaches than the germs 

 or spores of the saprolegnious fungus, which ordinarily causes a considera- 

 ble loss of eggs in the hatching-cones. The eggs attacked by the fungus 

 in the water first turn white; the egg-membrane then shows a disposi- 

 tion to wrinkle or become flaccid; the mycelium or growing stage of the 

 fungus is now in active progress. The mycelium is simply a felted mesh- 

 work of branching fungus cells, which appropriates the substance of the 

 egg and completely envelops its membrane. In this stage it is com- 

 paratively harmless ; afterwards from the felted mycelium threads club- 

 shaped cellular prolongations grow out, which radiate in all directions 

 like the seeds on a dandelion seed-head. In time each one of these club- 

 shaped heads of the iungus, to the number of hundreds on every affected 

 egg, develop a large number of spores or germs on the inside ; directly 

 the end bursts open and the minute spores swarm out of the club-shaped 

 spore-case in great numbers. Each of the spores is capable of indepen- 

 dent movement by means of long vibrating filaments attached to it at one 

 end. These wander about in the water, lodge on healthy eggs and grow 

 on and destroy them, so it is important that infested eggs should be 

 removed as soon as they make their appearance in the hatching appa- 

 ratus. Kiihne and Cohn have shown, however, that a temperature of 

 140° F. is sufficient to kill the germs of hacteria and other i^utrefactive 

 organisms, and it is very likely that such a temperature or less than the 

 boiling point of water, 212° F., would be quite sufficient to clear off and 

 kill any fungus germs which might adhere to the pans, trays, and cloths 

 used in the transportation of ova. 



The preceding account of the development, destructive growth, and 

 maturation of the spores is from personal observatioijs made on eggs 

 infested with fungus in the hatching-cones on the barges at Havre de 

 Grace in 1880, and it is onlj- introduced here to direct attention to some 

 possible means of staying or mitigating its ravages. I do not pretend 



