AFTER FECUNDATION. 



25 



very smooth. These boxes were then partly filled 

 ■with sand and gravel, and placed in running 

 ■water. They partially buried the boxes in the 

 gravelly bottom of the streams, and there exam- 

 ined them from time to time. Fig. 1 represents 

 one of these boxes. 



Fig. 1. Eemy's Box. 



The plan adopted by M. Oosta, at the College 

 of France is to arrange several parallel boxes, in 

 the form of steps, on each side of the principal 

 one, which is placed at the top of the series, from 

 which all the others are supplied with water, the 

 top one being supplied from a fountain, and the 

 supply of water being regulated by a stop-cock. 



