198 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



The manner of hatching heavy eggs in America in wooden troughs on wire 

 trays, in which the eggs are laid in the troughs, either in single rows, or arranged 

 one above the other, where they are washed by the water in the trough horizontally 

 (Atkins), or where the water runs down from above (Clark), or is forced up from below 

 (Williamson), seems to give as good results as can be desired, and the more complicated 

 troughs with their many partitions do not appear to do the work any more satis- 

 factorily. The simpler method, therefore, is much more in use. One apparatus, 

 which I only saw at the U. S. Fish Commission's excellent exhibition, but never any- 

 where in use, is Livingston Stone's apparatus, which consists of a Williamson trough 

 in which Mr. Stone, instead of a row of trays, had placed a basket made of wire cloth, 

 and then laid the roe in many layers one above the other. I have specially mentioned 

 this apparatus because many modifications of it have been introduced and are largely 

 used in Europe under the name of the Californian apparatus. 



The difference between the European modifications and the original American type 

 chiefly consists in the replacement of the Williamson wooden trough, with its many 

 divisions, by various small varnished tin boxes, each containing only one wire basket 

 in which the roe is laid. These baskets are generally so small that they will only hold 

 about 5,000 salmon or trout eggs. These so-called Californian apparatus are arranged 

 one below another in the form of steps, so that water can run down from one into the 

 other, and the results given are very good. Being of tin, and of small dimensions, 

 generally about 40 cm. long by 25 cm. broad and 25 cm. high, they are also easy 

 and convenient to handle. I also specially recommend to the American fish-breeder 

 Max von dem Borne's funnel-shaped apparatus, which, although giving excellent 

 results, only holds a few thousand salmon or trout eggs. It is especially suitable for 

 hatching the rarer kinds offish, of which there are only a small number to be had. 



Whilst Europe can still well compete with America in the breeding of trout and 

 salmon, and even has a station, Howietoun, in Scotland, which is larger than any in 

 America, the latter country is far ahead of Europe in the culture of fish with semi- 

 buoyant eggs, such as shad, whitefish, and pike perch. It is solely due to the self- 

 pickers, first introduced by Fred. Mather and Charles Bell, and afterwards improved 

 upon and perfected in various ways by Chase, Clark, Wilmot, and McDonald, that 

 this great fish-culture has been made possible. It would be difficult really to say 

 which of these four last constructions is the best for the purpose. I, for my part, 

 should be inclined to give the preference, on account of its simplicity, to the Wilmot 

 apparatus, which is made entirely of glass, but I think it would gain considerably in 

 effectiveness if the bottom were made a little broader in shape, like McDonald's appa- 

 ratus, and fitted, as his is, with three feet, by which a more regular circulation of water 

 would be obtained. During late years a glass self-picker, constructed by a Swiss named 

 Weiss, has also been successfully used in Switzerland and Germany. This has the 

 shape of a bottomless bottle, turned upside down, the water rising up through the neck 

 and running out over the edges of the bottom. 



Concerning the packing and transfer of eggs there is not much to be said. The 

 packing most used both in America and Europe is damp moss. On the other hand, 

 in Canada, where the eggs are hatched on trays of perforated zinc, the same trays 

 with a layer of moss on the eggs are often used for transferring them from the place 

 of fecundation to the fish-breeding stations. In this May one avoids moving the eggs 

 (which arc very delicate) for some time after fecundation, besides saving oneself the 



