556 EEPOET OF COMMISSIONER OF FISH AND FISHERIES. [18] 



in the box containing line ice until it was time to separate the fecundated 

 eggs from those which had not been fecundated, and which were opaque, 

 and from those which through contact with moss and alga had as- 

 sumed a bright blue color, so as to make them resemble colored crys- 

 tals.* The eggs were gradually hatched on Coste tables.t 



Hatching-houses. — It is my opinion that he who travels for the purpose 

 of obtaining a practical knowledge of the various aids employed in an 

 industry like fish-culture should pay more attention to a critical exam- 

 ination of the apparatus seen in operation in the various establishments 

 than to the extent to which this apparatus is employed, because this 

 will necessarily vary according to the funds at the disposal of the estab- 

 lishment and the importance of the operations to be performed. I shall 

 therefore not speak of the size of the various hatching-houses, but pass 

 in quick review the characteristic features which they must possess. 



The object of these houses is to protect both the hatching apparatus 

 and the persons who work them against the inclemencies of the weather. 

 If in case of necessity any kind of house or shed with windows suitably 

 placed may be converted into a hatching-house, it is none the less true 

 that buildings erected for the purpose, in a suitable position and fur- 

 nished with all the necessary requisites, will answer the purpose better. 

 Any one constructing such buildings should have due regard to the se- 

 verity of the weather, and provide them with sufficiently thick walls. 

 Thus at Cosmandorf the hatching-house has double walls of wood with 

 compressed straw between them. 



At Cosmandorf, Dachsen, and Apeldoorn the hatching-chambers are 

 also of wood. The large hatching-room at Berneuchen has three 

 walls of wood, the fourth being of brick, formed by the same canal 

 which carries the water into the establishment. The roof is formed of 

 wooden slats, covered both on the inside and outside with tarred paste- 

 board. The placing of the hatching-chamber in the ground made nec- 

 essary by the hydraulic movement also serves the economical purpose 

 of affording protection to the water and the apparatus against the ex- 

 cessive cold of the winter. 



I have already referred to the hatching-canals at Hiiningen, which 

 run in the pavement, as being made necessary by the circumstance that 

 the water has to be brought from a spring which rises at too low a level; 

 but they may also serve to keep the water from freezing. Whenever 



* It seems to me that the vegetation which endangers packed eggs is perhaps 

 favored by the finish of the cloth in which they are wrapped and on which they rest. 

 I would therefore recommend the use of cloth without any finish, or from which it 

 has been removed by a solution of lye. 



I I saw at Seewieso an ice box for transporting Thymallus eggs to the establishment 

 from the place where the eggs had been fecundated. This apparatus had the dimen- 

 sions of an ordinary Dillon vessel used by herbalists, and is made of tin by Joseph 

 Sihwarz-Spengler, in St. Polten, and like this can be carried slung over the shoulder. 

 It contains six frames for eggs, and a seventh (the top one) for ice. • It has two pan- 

 els, one for lowering what constitutes the long side of the parallelopiped box, the 

 other to raise the upper side. 



