[17] FISH CULTURE IN CENTRAL EUROPE. 555 



as well as healthy, than his establishment, where you can approach the 

 tanks containing the apparatus through which the water runs ou any 

 side without wetting* your feet. 



I may pass iu silence the Lavallette troughs (which I saw at Seewiese), 

 and the Zug apparatus (which I saw at Zurich) ; the first, because made 

 of porcelain, has a surface perforated by only a few and large holes; 

 and for the second automatic selectors have been substituted to ad- 

 vantage. 



To some extent ice boxes may be considered as belonging to the 

 batching apparatus. They consist of prismatic or cubic boxes with 

 thick walls of wood, sometimes lined on the outside with zinc. In 

 these boxes, which may have a double lid, are placed, at a suitable dis- 

 tance, one above the other, several frames with a perforated wooden or 

 wire bottom. On these the eggs are placed on moist cloths. On the 

 top frame ice is placed which lets its cold drippings pass through the 

 perforated bottom. In this manner eggs have been shipped a long dis- 

 tance, and the embryonal development has been delayed. 



Iu reviewing the character of the hatching apparatus which I saw in 

 operation, I would say : 



1. That on account of their convenience (suitable height of the appa- 

 ratus) troughs of any kind of material, and hatching tables of the height 

 of an ordinary table, are equally to be recommended. 



2. Troughs of cement and metal are preferable on 'account of the 

 durability of the material, and because they can easily be kept clean. 



3. On account of the proper hydraulic movement all those apparatus 

 are to be preferred in which the water runs among the eggs placed at 

 its bottom. 



I. An arrangement by which the eggs are more scattered is not to 

 be recommended, unless the abundant and rapid renewal of the " -iter 

 fulfills the third condition. 



5. Owing to the greater facility with which the spoiled eggs can be 

 picked out from among the sound ones, those methods are to be pre- 

 ferred, by which the eggs are placed in a single layer. 



(>. I consider it better to place the eggs ou frames of netting in pref- 

 erence to placing them ou fine gravel, or directly at the bottom of the 

 trough ; the best kind of frame is that which allows the water to pass 

 through easily (wire netting), and which has perforated edges. 



7. All the hatching apparatus which I have seen answers the pur- 

 pose more or less, but the ordinary California trough excels them all, 

 because it meets all the desired requirements. 



8. Automatic selectors are particularly suited for the hatching of eggs 

 of Coregoni ; while the ordinary California trough is specially adapted 

 to the hatching of the eggs of salmonoids. 



At Hiiuingen I saw in operation the Haack apparatus. It was there 

 employed for Coregonus eggs from the Lake of Constance, which w T ere 

 hatched at the expense of the Italian Government. The eggs remained 



