A Dryx rw antmate Nature. 383 
eS SS 
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 eges during the time of incubation. The water is there- 
