29 



receptacle. Formerly, the practice obtained of having 

 this basin full of water, under the idea that such arrange- 

 ment more nearly reproduced the natural conditions, but 

 subsequent discoveries led to a change of this method. 

 The ova are fertilized by'the^spermatozoa of the milt 

 entering through the micropyle and taking^up board and 

 lodging within. 



It was ascertained however, in practice, that these 

 spermatozoa, little tadpoles as they appear to be under 

 the microscope, were not fond of water, and although 

 very active when first emitted, soon perished in the water. 

 They retained their vitality much longer when dropped 

 among the ova in a comparatively dry state, and this is 

 the method universally pursued at present. The result 

 of the change was very great; on the earlier plan not 

 more than one egg in three or four was vitalized, where- 

 as now, fully ninety eight per cent, are made capable of 

 producing young as we have already mentioned^ and as 

 will be more fully explained hereafter when we come to 

 special and particular directions for each part of the 

 process. 



The eggs mature in comparative safety. Some die, of 

 course, others were never properly impregnated, but the 

 percentage is small, not more than five or ten per cent, 

 of the whole. In the natural method probably not one 

 in five hundred, certainly not one in a hundred survives 

 to mature and produce a perfect fish. By the artificial 

 plan, and at the lowest calculation, fully ninety in every 

 hundred are saved and developed. Here is the great 

 gain in fish culture. It is in the primary stages that the 

 advantage is secured. Say that afterwards the perils are 

 alike and still see the enormous difference in its favor. 

 Allow that young fish after their birth are in continued 

 peril ot their lives ; that enemies still pursue and waylay, 



