548 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [10] 



2. They should economize space as much as is compatible with the 

 proper performance of the hatching operation and with the least possi- 

 ble hinderance to the renewal of the water. 



3. They should be constructed of impervious, durable, and clean ma- 

 terials. 



4. They should be jdaced in such a manner as to facilitate the opera- 

 tions which should be carried on during the hatching process, especially 

 the separation of the spoiled eggs from the healthy ones. 



According to their typical character I .may classify the hatching ap- 

 paratus which I have seen in operation as follows : 



1. Caste's system: (1) Stairs of troughs; (2) hatching tables 5 (3) sub- 

 terranean canals. 



2. Simple troughs: (1) Troughs of carbonized wood; (2) troughs of 

 cement or zinc. 



3. Hatching tables : (1) Williamson tables ; (2) Zenk tables. 



4. Bolton's system : Holton hatching apparatus. 



5. California troughs: (1) Eckardt troughs; (2) California boxes; 

 (3) funnel-shaped troughs ; (4) automatic selectors. 



6. Ice boxes : The Haack bos. 



The defects of the Coste troughs are well known, and have been 

 clearly shown as fish-culture has further advanced. It is, therefore, 

 not astonishing that they have been everywhere abandoned, even at 

 Hiiningen, where the present director of the establishment does not use 

 them at all. I saw a Coste stairway in white enameled clay at Neu- 

 hausen, but it was not in use. Hatching tables (Coste's system) I saw, 

 however, at Hiiningen, where they are still used, and form part of the 

 material which the imperial German Government acquired with the 

 establishment. These tables are about a meter long, with a somewhat 

 deep edge, and are placed on an incline ; the first receives the water 

 direct from a spout in the short side of the table. A perforated parti- 

 tion of zinc plate, running parallel with the lower edge, lets the water 

 pass, which then flows from this edge through small leaden pipes upon 

 the table placed below. Some of these pipes are kept closed with a 

 stopper, while others are left entirely open, so as to maintain the desired 

 level. The large compartment (lined on the inside with ^inc) is placed 

 between the edge and the partition running parallel with the lower 

 edge, and is destined for the eggs, which are placed on a soft bed sup- 

 ported by the well-known network of glass stems, for which, in some 

 cases, a more economical construction of metal wire is substituted. 

 • Similar to the Coste tables are the large troughs in cement, placed on 

 an incline, which fill the large hatching-hall of the Velp establishment. 

 They are placed in a row of five double compartments having a com- 

 mon edge, and leading to a compartment which is double the size of the 

 others, and which is the last of the row. Some troughs intended for 

 hatching are 8G centimeters [about 34 inches] broad and 2 meters [about 

 79 inches] long. Here likewise the eggs are placed on Coste frames, 



