An Automatic Aerating Apparatus. By F. G. Gemmill. 13 



The aerator has been fully tested in the Embryology Laboratory 

 at Glasgow University during the eight months that have elapsed 

 since the author first employed it there in its present form. A 

 similar instrument fitted up by him at the Millport Marine Station 

 in the beginning of September last has also worked with regu- 

 larity. It was at the latter Institution, several years ago, that 

 his first experiments directed towards designing such an aerator 

 were made. 



