260 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Doubtless it makes a great difference ^Ybetber tbe milt is mixed 

 thorougbly with tbe water, or is permitted to settle in a body to the 

 bottom, as it will wben dropped gently into water. In tbe latter case 

 tbe water may not gain access to tbe main mass of tbe milt for some 

 time. 



9. — DURATION OP CONTACT NECESSARY TO INSURE FECUNDATION. 



In tbe ordinary course of procedure tbe milt was in contact with tbe 

 eggs not far from a minute before tbe application of water, and from 

 twenty minutes to an bour, or even longer, tbereafter. In two instances, 

 immediately after tbe application of tbe milt and tbe stirring of tbe 

 eggsenougb to diffuse it among tbem, it was wasbed off" by rinsing tbe 

 eggs several times witb clean water, tbe wbole being done with tbe 

 utmost possible dispatcb. 



Uxperhnent 14. — Lot 125, containing 3,300 eggs ; tbe eggs were rinsed 

 witb clean water immediately after milting ; fecundation, 100 per cent* 



Experiment 15. — Lot 127, containing 2,700 eggs ; rinsed immediately 

 after milting; fecundation, 100 per cent. 



From tbis it appears tbat fecundation is effected so quickly tbat, for 

 practical purx)oses, it may be considered instantaneous. 



10. — TEMPERATURE OF "«VATER AND DEVELOPMENT OF EGGS. 



Tbe temperature of tbe water in tbe batcbing-house wben tbe first 

 eggs were deposited, was 44° F., and tbey developed rapidly. On tbe 

 3d day of November it bad fallen to 42°. and from tbat time till tbe 16tb 

 it vibrated between 42^° and 39°. On tbe 20tb it sunk to 37^, and on 

 tbe 21st to 35*^. About tbis point it remained until tbe last week in 

 December, wben it sunk to 33°, tbe temperature of tbe air outside being 

 — 19°. During tbe rest of tbe winter it generally stood at 33-^° or 34°, 

 occasionally rising to 3G°. In tbe spring it sunk instead of rising, tbe 

 water being colder during tbe first balf of April tban at any otber time 

 •during tbe season. This I attribute to tbe abundance of snow and ice- 

 water running into tbe brook at tbat time. No difficulty was experi- 

 enced in keeping the building warm enough to avoid any injurious freez- 

 ing, although on several occasions, wben the night was extremely cold 

 and tbe fires dull, ice formed in some of tbe troughs. 



In tbis extremely cold water, of course tbe development of the eggs 

 was very slow. In tbe first lot the heart of the embryo was beating 

 December 10, but tbe eyes were not black until January 9, seventy- 

 three days from fecundation. In spring- water tbe same stage would be 

 reached in about thirty days. On the 7tb day of February tbe circula- 

 tion was barely established in tbe embryos taken November 21. In 

 those taken November 14 it was distinct and the embryos active ', in 

 those of November 9 the circulation was stronger and the embryos 

 larger, but there was still no sign of color in the eyes, although ninety 

 days had passed since fecundation. Tbe only disadvantage in this slow 



