552 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [14] 



introduced some modifications in it), it forms part of the apparatus which 

 has been acquired during his directorship. At Himiugeii I have also 

 seen California troughs in use in the open air. 



=1 



V 



1 ' ' . 



SECTION OF THOUGH. 



ZEXK THOUGH. 



