E. B. PRED 629 



beaker and cylinder are included. The neck is plugged with cotton 

 and the top of the pot is covered with several layers of cotton. One 

 end of the glass cylinder is protected in the same way while the other 

 end is covered with a glass beaker. It is well to have a layer of 

 non-absorbent cotton between the beaker and the glass cylinder. 

 After sterilization, the cotton covers are removed and one end of the 

 cylinder is fitted to the shoulder at the top of the pot. By means 

 of large sterilized pipettes, it is easy to add water through the neck 

 into the pot. The different parts of the apparatus are shown in Fig. 2, 

 In order to give better aeration, the beaker may be raised from the 

 top of the cylinder, as shown in Fig. 3, and wire supports used to 

 hold the beaker in place. This apparatus is easy to handle and may 

 be sterilized repeatedly without cracking. 



Several tests have been made of this apparatus under greenhouse 

 conditions. If the apparatus is sterihzed and sufficient care is exer- 

 cised in watering, plants may be grown for several months without 

 danger of becoming contaminated. 



