212 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



above this, there is no current towards the perforated ring of the cir- 

 cumference: and the young fish are not exposed to any injury, especi- 

 ally of the umbilical bag, by being driven against the sides of the 

 vessel, which danger is in other apparatus averted by large and incon- 

 venient sieve-like frames. 



What are known as " catch-boxes" (Fangkasten) are entirely unneces- 

 sary, as the fish which may happen to slip out have still above them a 



Fig 4. 



space 5 centimeters in height, free of water, and there is therefore no 

 chance whatever of their escaping. Unless, for some special reason, it 

 is deemed desirable to place them in a larger body of water, the fish 

 may safely be left in the apparatus till they are fully developed. 



Although this apparatus can easily hold 5,000 eggs, it takes up very 

 little room, is clean, and easily handled. 



By lifting and pressing down the inner vessel the eggs can easily be 

 moved for the purpose of picking them over. 



It is true that faience, like so many of our household utensils, is frag- 

 ile. If, therefore, the person who is to handle the apparatus suffers 

 from chronic clumsiness, it may be constructed of tin, wood, stone, or 

 cement. 



This hatching-pot cannot be considered expensive, certainly not more 

 expensive than other apparatus of this kind, as it may be obtained at 

 the reasonable price of 10 marks ($2.38) from the porcelain and faience 

 factory of Ludwig Wessel, in Bonn. 



