404 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



there be a sufficient change to prevent stagnation, with the 

 depth not less than four feet, that they be not too much 

 crowded, that the bottom be not newly submerged, that the 

 water be not too transparent, and, in the case of a brook, that 

 there be not a large percentage of water from springs in the 

 immediate vicinity. 



A most important fact ascertained was the possibility of 

 what is known as the dry process of fertilizing the eggs. 

 The usual practice has been to squeeze out the eggs and milt 

 into a dish of water, and to secure contact by stirring the 

 water ; but it has been ascertained that the less water there 

 is with the eggs, the more effectual is the application of the 

 milt, and the nearest approach to perfect success is in the en- 

 tire absence of water. 



In these experiments the eggs were squeezed from the bel- 

 ly of the living female into a dry tin pan, and, when all had 

 been obtained, a living male was taken, and, being held over 

 the pan, his milt was forced into it. Being of the consistency 

 of cream, this milt does not immediately spread over all the 

 eggs, and it is necessary to give this a motion over the bot- 

 tom of the pan until contact has been effected. After this, 

 and not sooner, water is to be added. The theory of this 

 process lies in the alleged fact that the milt loses all its po- 

 tency within two minutes, at the longest, after it is put into 

 the water ; so that, unless discharged in a perfectly fresh con- 

 dition, so that it will be carried immediately in contact with 

 the eggs, the latter will fail of fecundation. When not min- 

 gled with water, the milt, it is said, can be kept in a bottle 

 for days and still retain its power of fertilization a fact of 

 which important application will doubtless be made hereafter 

 in fish-breeding. 



This process of dry fecundation, as it is called, is the dis- 

 covery of a Russian gentleman, Mr. Vrasski, and was, we un- 

 derstand, first introduced to the notice of American fish-cul- 

 turists by Mr. G. Sheppard Page ; and it is said that while by 

 the old method only 65 per cent, of eggs are fecundated, by 

 the new one the average is 96 per cent. These facts were 

 prominently brought before the convention of fish-culturists 

 held at Albany in February last, and will doubtless be taken 

 into proper account in all future experiments. 



