A LINK IN ANIMATE NATUKE. 



383 



plied from a reservoir by a pipe running through a dry-air 

 refrigerator (or through a chest filled with ice), by which 

 modern American invention the temperature may be regu- 

 lated at any degree required between freezing and ten de- 

 grees below zero. The pipe should be coiled in the refrig- 

 erator. 



The aquarium presented above is the one selected by the 

 College of France from numerous samples, and it has proved 

 a success; but the object of it is more especially for studying 

 the eggs during the time of incubation. The water is there- 



