BULLETIN OF THE UNITED STATES FISH COMMISSION. 263 



To do this will probably cause the rapid death of organisms of so deli- 

 cate a nature as j'oung fish. 



There is an aerating apparatus consisting of a simple syringe fur- 

 nished with a perforated mouth-piece. To renew the air, one breathes 

 by means of the syringe into the water of the apparatus, and then places 

 the mouth-piece at a short distance from the surface of the water, and 

 makes the piston go down, not losing sight of the circumstance that lit- 

 tle fish of a very delicate nature are concerned. The air should, there- 

 fore, not be blown into the water too violently. 



Benewiiuj the icater. — When the distance to be traveled is very great, 

 it will be well, whenever a favorable opportunity otters, to renew the 

 water in the apparatus. To do this, one should have clear and drinka- 

 ble water. In no case should muddy water, containing impurities, be 

 employed. To renew the water in the apparatus, one inclines the tube 

 C, so as to make the water flow off slowly; then he adds slowly, through 

 the ice-box, new water, so as gradually to change the temi)erature of 

 the element in which the young fish are kept. Too sudden a change of 

 temperature would endanger the life of the young fish. 



SI.— NOTES OIV HATCHINC; AIVO PJLANTIIVG YOUIVG FISH IIV ITAt-IAlV 



i;VATEKS.* 



By Prof. PIETRO PAVESI. 



In an address on fish-culture, delivered February 27, 1885, I stated 

 that lavarets {Coregonus wartmanni) from the Lake of Constance had 

 been placed iu Italian waters at Lario at two different times (on Febru - 

 ary 27 and IMarch 5), when the young fish had almost lost their umbili- 

 cal sacs, and measured about 11 millimeters [nearly one-half inch] in 

 length. Doubts were expressed as to the success of this experiment, 

 but the eggs hatched. After the yoitng fish appeared, however, the 

 usual mold was observed. There are two suppositions to account for 

 this mold : one, that it is caused by the quality of the water used in 

 the hatching apparatus, in which case filters of the Waplitz model will 

 have to be employed ; the other, that some of the shells of the eggs 

 broke in transportation and thus favored the development of mold. 



I have now to report that my experiments resulted successfully. 

 During October, November, and December, 1885, a number of little 

 fish were caught near Bellano, which were about 4^ inches long, and in 

 shape and color bore a strong resemblance to the fry I had planted. 

 The fishermen cooked and ate some and found their flavor excellent, 

 while some specimens that were sent to me here leave no doubt as to 

 their being the same fish {Coregoni) planted by me. By planting more 



•These notes are taken from an open letter to Prof. B. Benecke, of Konigsberg^ 

 Germany, which is extracted from the report of the Italian Society of Natural Science, 

 Milan, 1866. Translated from the Italian by Hkrman Jacobson. 



