12 



Methods of Working 



root is in the liquid while the cotyledons rest on the surface. As soon 

 as sufficient growth has been made the papers are replaced by corks, 

 the remnants of the seeds still being kept on top in the air. Other 



rr -= -c 



B 



--c 



Fig. 1. Diagrammatic sketches showing methods of setting up water cultures. 



A. a. Seedling of cereal. 



b. Cork bored with two holes, and cut into two pieces through one hole. 



c. Food solution. 



B. a. Pea seedling. 



&. Paper shield which supports the seedling. 



c. Brown paper cover over bottle of food solution. 



plants are treated according to their individual needs and mode of 

 germination (Fig. 1). 



The constitution of the nutritive solution is important, and it is 

 becoming more and more evident that different plants have different 



