350 THE YEAR-BOOK OF AGRICULTURE. 



with a goose-quill or soft brush, moving the quill or brush briskly about in the water, and 

 then suffer it to run off. Repeat this process until the water is free from sediment, and runs 

 off clear ; or the eggs may be removed into a vessel filled with clean water, with a skimmer, 

 there to remain while the boxes are being cleansed. The hatching-boxes should be grated, 

 on that side from which the water escapes, with wire cloth, the meshes of which should be 

 sufficiently fine to prevent the eggs, or the young fish, when they make their appearance, 

 from passing out. A very neat and convenient hatching apparatus is the flat wicker-basket, 

 the interstices of which are fine enough to prevent the eggs from passing through. These 

 baskets are to be placed in running water. Care, however, must be taken, as well as with 

 all other apparatus for the same purpose, that a place be selected where the current of the 

 water is not so rapid as to wash or pile the eggs up in the end opposite to where the water 

 enters. Whenever the baskets become foul by sediment or vegetable matter, the eggs can be 

 transferred to a clean one, and the basket cleansed. A conduit or flume must be con- 

 structed, of plank or boards, to contain a sufficient depth of water, in which the baskets are 

 to be placed. The utmost cleanliness is absolutely necessary during the whole time of incu- 

 bation ; it is one of the essentials to insure success. 



The method adopted by Gehen and Remy was to place the eggs in zinc boxes of about one 

 foot diameter, with a lid or cover on them, and the sides of each box being pierced full of 

 small holes, care being taken to have the edges of the holes very smooth. These boxes, then, 

 were partly filled with sand and gravel, and then placed in running water. They partially 

 buried the boxes in the gravelly bottom of the streams, and there examined them from time 

 to time. The plan adopted by M. Costa, at the College of France, is to arrange several pa- 

 rallel boxes, in the form of steps, on each side of the principal one, which is placed at the top 

 of the series, from which all the others are supplied with water, the top one being supplied 

 from a fountain, and the supply of water being regulated by a stop-cock. In this case the 

 eggs are placed on willow hurdles instead of gravel. 



Whatever plan may be adopted, great care and watchfulness are essentially necessary to 

 insure success. A vegetable parasite, termed by naturalists Byssus, frequently attaches 

 itself to the eggs, and destroys them. The best way to remedy this evil is, to remove very 

 carefully all the eggs that are free from the parasite, and throw those away which have been 

 attacked, and at the same time thoroughly cleanse the boxes or baskets. 



Fish-breeding in France. 



IN a recent visit to the fish-hatching establishment of M. Coste, in Paris, the French 

 Minister of Agriculture reports that he found there two hundred and fifty thousand newly- 

 hatched fish, one hundred and fifty thousand of which had only just been brought up from 

 the establishment at Huniguen. All this large number were conveyed to Paris at the same 

 time, and without a perceptible loss. The fish comprised common trout, trout from the 

 lakes, salmon from the Rhine, and trout from the Swiss lakes. 



Growth of Fish. 



WHILE Pisciculture is gaining ground in every country in modern, Europe, it may be 

 amusing to our readers to publish certain facts within our own knowledge relative to the 

 increase in size of fish in particular waters in Belgium. The growth of the salmon, as 

 proved by the marked fish in the Scotch fisheries, is notorious, and has already been fully 

 noticed. In four months' time, it has been proved that the young fry, between the period of 

 their leaving their native rivers for the sea and their return, have increased in weight varying 

 from three to seven pounds. Without the positive proof of identity by marking, this would 

 have been considered wholly chimerical. We have now to notice the increase, in the 

 waters at Boitsfort, near Brussels, of the jack, the only species of fresh-water fish which has 

 as yet been put to the test in regard to its growth. In these waters, in October, in 1852, 

 about two thousand were left as stock, none exceeding two pounds in weight, the fish 

 thus put in being indigenous to the water ; these fish have been caught the present month 





