574 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



hands carefully so that water could nowhere gather. Theu i^our the 

 roe in a " dry " state on the bottom of the vessel. 



5. If the drying-process has been well done, so that no swelling of 

 the eggs can take place, take up without any too great hurry the fish 

 containing the milt, dry it like the other one, and pour the milt over the 

 eggs so as to cover the largest possible number. A quantity of milt 

 which only gives the water — to be poured in afterward — a slightly whit- 

 ish color is sufficient. The pouring over of the milt should be done 

 quickly. With fish of the species of Salmo and Trutta a quarter of an 

 hour may intervene bet«^een putting the roe in the vessel and pouring 

 in the milt, provided all the other conditions are favorable. 



6. As soon as the milt has been poured in, pour over the water as 

 quickly and as suddenly as possible, so as just to cover the eggs with 

 water, and stir the mixture with the hand, letting it rapidly describe a 

 circular motion on the bottom of the vessel. 



7. Let the whole stand for a while, this period of standing to be reg- 

 ulated by the degree of stickiness of the roe and its power of swelling; 

 sometimes amounting to less than a minute, sometimes to more than an 

 hour. The impregnation commences in a short time, and it is therefore 

 advisable to clear the milky water after a few minutes by pouring in 

 clear water. The object of this period of standing is to diminish the 

 sticking capacity of the eggs, which is strongest in the beginning, but 

 which constantly decreases; also to insure in some species of eggs their 

 complete development to the quickly-increasing spherical form, to make 

 them gradually grow harder before placing them in the traUv«porting- 

 vessels, and thus to prevent their pressing each other too much. 



8. Before placing the impregnated roe in the transporting- vessels, 

 loosen it carefully with a quill-pen from the watery bottom of the first 

 vessel. 



9. Never fail to select vessels of considerable size for such species of 

 roe as swell rapidly, so that the eggs can lie loosely without pressing on 

 each other. All vessels used for this purpose should therefore have a 

 fiat bottom. 



Whenever the milt is scarce, it may be recommended to use smaller 

 vessels, so as to concentrate it as much as possible. Whenever this is 

 done, it will be well, after having stirred the roe and milt with water, to 

 pour it into a larger vessel with some water, and let it stand in this. 



If this is neglected, the eggs will frequently be exposed to too great a 

 pressure. Such eggs as do not contain the necessary space for de- 

 veloping the young fish will produce weak or deformed fish. With roe of 

 the species of Sahno and Trutta this precaution is unnecessary, as well 

 as with all those species of eggs which do not change their shape when 

 exposed to pressure. 



To employ the '' dry method of impregnation" in all cases is not advisa- 

 ble, as the " moist" method is simpler, and in most cases proves successful. 



The " dry " method, however, nuist absolutelij be emploj'ed with all those 



